2547 lines
88 KiB
HTML
2547 lines
88 KiB
HTML
<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<meta name="generator" content="Asciidoctor 1.5.8">
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<meta name="author" content="Beman Dawes, Christopher Kohlhoff, Peter Dimov">
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<title>Boost.System: Extensible Error Reporting</title>
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<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700">
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<style>
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/* Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
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/* Uncomment @import statement below to use as custom stylesheet */
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/*@import "https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700";*/
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article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
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audio,canvas,video{display:inline-block}
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audio:not([controls]){display:none;height:0}
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script{display:none!important}
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html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
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a{background:transparent}
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a:focus{outline:thin dotted}
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a:active,a:hover{outline:0}
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h1{font-size:2em;margin:.67em 0}
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abbr[title]{border-bottom:1px dotted}
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b,strong{font-weight:bold}
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dfn{font-style:italic}
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hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
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mark{background:#ff0;color:#000}
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code,kbd,pre,samp{font-family:monospace;font-size:1em}
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pre{white-space:pre-wrap}
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q{quotes:"\201C" "\201D" "\2018" "\2019"}
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small{font-size:80%}
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sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
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sup{top:-.5em}
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sub{bottom:-.25em}
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img{border:0}
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svg:not(:root){overflow:hidden}
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figure{margin:0}
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fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
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legend{border:0;padding:0}
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button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
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button,input{line-height:normal}
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button,select{text-transform:none}
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button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
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button[disabled],html input[disabled]{cursor:default}
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input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
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button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
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textarea{overflow:auto;vertical-align:top}
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table{border-collapse:collapse;border-spacing:0}
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*,*::before,*::after{-moz-box-sizing:border-box;-webkit-box-sizing:border-box;box-sizing:border-box}
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html,body{font-size:100%}
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body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;font-weight:400;font-style:normal;line-height:1;position:relative;cursor:auto;tab-size:4;-moz-osx-font-smoothing:grayscale;-webkit-font-smoothing:antialiased}
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a:hover{cursor:pointer}
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img,object,embed{max-width:100%;height:auto}
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object,embed{height:100%}
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img{-ms-interpolation-mode:bicubic}
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.left{float:left!important}
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.right{float:right!important}
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.text-left{text-align:left!important}
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.text-right{text-align:right!important}
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.text-center{text-align:center!important}
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.text-justify{text-align:justify!important}
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.hide{display:none}
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img,object,svg{display:inline-block;vertical-align:middle}
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textarea{height:auto;min-height:50px}
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select{width:100%}
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.stretch{width:100%}
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.subheader,.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{line-height:1.45;color:#7a2518;font-weight:400;margin-top:0;margin-bottom:.25em}
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div,dl,dt,dd,ul,ol,li,h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6,pre,form,p,blockquote,th,td{margin:0;padding:0;direction:ltr}
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a{color:#2156a5;text-decoration:underline;line-height:inherit}
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a:hover,a:focus{color:#1d4b8f}
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a img{border:none}
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p{font-family:inherit;font-weight:400;font-size:1em;line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
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p aside{font-size:.875em;line-height:1.35;font-style:italic}
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h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{font-family:"Open Sans","DejaVu Sans",sans-serif;font-weight:300;font-style:normal;color:#ba3925;text-rendering:optimizeLegibility;margin-top:1em;margin-bottom:.5em;line-height:1.0125em}
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h1 small,h2 small,h3 small,#toctitle small,.sidebarblock>.content>.title small,h4 small,h5 small,h6 small{font-size:60%;color:#e99b8f;line-height:0}
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h1{font-size:2.125em}
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h2{font-size:1.6875em}
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h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em}
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h4,h5{font-size:1.125em}
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h6{font-size:1em}
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hr{border:solid #dddddf;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em;height:0}
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em,i{font-style:italic;line-height:inherit}
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strong,b{font-weight:bold;line-height:inherit}
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small{font-size:60%;line-height:inherit}
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code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
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ul,ol,dl{font-size:1em;line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
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ul,ol{margin-left:1.5em}
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ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
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ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
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ul.square{list-style-type:square}
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ul.circle{list-style-type:circle}
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ul.disc{list-style-type:disc}
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ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
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dl dt{margin-bottom:.3125em;font-weight:bold}
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dl dd{margin-bottom:1.25em}
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abbr,acronym{text-transform:uppercase;font-size:90%;color:rgba(0,0,0,.8);border-bottom:1px dotted #ddd;cursor:help}
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abbr{text-transform:none}
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blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
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blockquote cite{display:block;font-size:.9375em;color:rgba(0,0,0,.6)}
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blockquote cite::before{content:"\2014 \0020"}
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blockquote cite a,blockquote cite a:visited{color:rgba(0,0,0,.6)}
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blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
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@media screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
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h1{font-size:2.75em}
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h2{font-size:2.3125em}
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h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
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h4{font-size:1.4375em}}
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table{background:#fff;margin-bottom:1.25em;border:solid 1px #dedede}
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table thead,table tfoot{background:#f7f8f7}
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table thead tr th,table thead tr td,table tfoot tr th,table tfoot tr td{padding:.5em .625em .625em;font-size:inherit;color:rgba(0,0,0,.8);text-align:left}
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table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
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table tr.even,table tr.alt,table tr:nth-of-type(even){background:#f8f8f7}
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table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{display:table-cell;line-height:1.6}
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h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
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h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
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.clearfix::before,.clearfix::after,.float-group::before,.float-group::after{content:" ";display:table}
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.clearfix::after,.float-group::after{clear:both}
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*:not(pre)>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background-color:#f7f7f8;-webkit-border-radius:4px;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed;word-wrap:break-word}
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*:not(pre)>code.nobreak{word-wrap:normal}
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*:not(pre)>code.nowrap{white-space:nowrap}
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pre,pre>code{line-height:1.45;color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;text-rendering:optimizeSpeed}
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em em{font-style:normal}
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strong strong{font-weight:400}
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.keyseq{color:rgba(51,51,51,.8)}
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kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background-color:#f7f7f7;border:1px solid #ccc;-webkit-border-radius:3px;border-radius:3px;-webkit-box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em white inset;box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em #fff inset;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
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.keyseq kbd:first-child{margin-left:0}
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.keyseq kbd:last-child{margin-right:0}
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.menuseq,.menuref{color:#000}
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.menuseq b:not(.caret),.menuref{font-weight:inherit}
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.menuseq{word-spacing:-.02em}
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.menuseq b.caret{font-size:1.25em;line-height:.8}
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.menuseq i.caret{font-weight:bold;text-align:center;width:.45em}
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b.button::before,b.button::after{position:relative;top:-1px;font-weight:400}
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b.button::before{content:"[";padding:0 3px 0 2px}
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b.button::after{content:"]";padding:0 2px 0 3px}
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p a>code:hover{color:rgba(0,0,0,.9)}
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#header,#content,#footnotes,#footer{width:100%;margin-left:auto;margin-right:auto;margin-top:0;margin-bottom:0;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em}
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#header::before,#header::after,#content::before,#content::after,#footnotes::before,#footnotes::after,#footer::before,#footer::after{content:" ";display:table}
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#header::after,#content::after,#footnotes::after,#footer::after{clear:both}
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#content{margin-top:1.25em}
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#content::before{content:none}
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#header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
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#header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #dddddf}
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#header>h1:only-child,body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #dddddf;padding-bottom:8px}
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#header .details{border-bottom:1px solid #dddddf;line-height:1.45;padding-top:.25em;padding-bottom:.25em;padding-left:.25em;color:rgba(0,0,0,.6);display:-ms-flexbox;display:-webkit-flex;display:flex;-ms-flex-flow:row wrap;-webkit-flex-flow:row wrap;flex-flow:row wrap}
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#header .details span:first-child{margin-left:-.125em}
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#header .details span.email a{color:rgba(0,0,0,.85)}
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#header .details br{display:none}
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#header .details br+span::before{content:"\00a0\2013\00a0"}
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#header .details br+span.author::before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
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#header .details br+span#revremark::before{content:"\00a0|\00a0"}
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#header #revnumber{text-transform:capitalize}
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#header #revnumber::after{content:"\00a0"}
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#content>h1:first-child:not([class]){color:rgba(0,0,0,.85);border-bottom:1px solid #dddddf;padding-bottom:8px;margin-top:0;padding-top:1rem;margin-bottom:1.25rem}
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#toc{border-bottom:1px solid #e7e7e9;padding-bottom:.5em}
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#toc>ul{margin-left:.125em}
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#toc ul.sectlevel0>li>a{font-style:italic}
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#toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
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#toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
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#toc li{line-height:1.3334;margin-top:.3334em}
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#toc a{text-decoration:none}
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#toc a:active{text-decoration:underline}
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#toctitle{color:#7a2518;font-size:1.2em}
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@media screen and (min-width:768px){#toctitle{font-size:1.375em}
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body.toc2{padding-left:15em;padding-right:0}
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#toc.toc2{margin-top:0!important;background-color:#f8f8f7;position:fixed;width:15em;left:0;top:0;border-right:1px solid #e7e7e9;border-top-width:0!important;border-bottom-width:0!important;z-index:1000;padding:1.25em 1em;height:100%;overflow:auto}
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#toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
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#toc.toc2>ul{font-size:.9em;margin-bottom:0}
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#toc.toc2 ul ul{margin-left:0;padding-left:1em}
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#toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
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body.toc2.toc-right{padding-left:0;padding-right:15em}
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body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #e7e7e9;left:auto;right:0}}
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@media screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
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#toc.toc2{width:20em}
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#toc.toc2 #toctitle{font-size:1.375em}
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#toc.toc2>ul{font-size:.95em}
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#toc.toc2 ul ul{padding-left:1.25em}
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body.toc2.toc-right{padding-left:0;padding-right:20em}}
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#content #toc{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
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#content #toc>:first-child{margin-top:0}
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#content #toc>:last-child{margin-bottom:0}
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#footer{max-width:100%;background-color:rgba(0,0,0,.8);padding:1.25em}
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#footer-text{color:rgba(255,255,255,.8);line-height:1.44}
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#content{margin-bottom:.625em}
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.sect1{padding-bottom:.625em}
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@media screen and (min-width:768px){#content{margin-bottom:1.25em}
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.sect1{padding-bottom:1.25em}}
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.sect1:last-child{padding-bottom:0}
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.sect1+.sect1{border-top:1px solid #e7e7e9}
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#content h1>a.anchor,h2>a.anchor,h3>a.anchor,#toctitle>a.anchor,.sidebarblock>.content>.title>a.anchor,h4>a.anchor,h5>a.anchor,h6>a.anchor{position:absolute;z-index:1001;width:1.5ex;margin-left:-1.5ex;display:block;text-decoration:none!important;visibility:hidden;text-align:center;font-weight:400}
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#content h1>a.anchor::before,h2>a.anchor::before,h3>a.anchor::before,#toctitle>a.anchor::before,.sidebarblock>.content>.title>a.anchor::before,h4>a.anchor::before,h5>a.anchor::before,h6>a.anchor::before{content:"\00A7";font-size:.85em;display:block;padding-top:.1em}
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#content h1:hover>a.anchor,#content h1>a.anchor:hover,h2:hover>a.anchor,h2>a.anchor:hover,h3:hover>a.anchor,#toctitle:hover>a.anchor,.sidebarblock>.content>.title:hover>a.anchor,h3>a.anchor:hover,#toctitle>a.anchor:hover,.sidebarblock>.content>.title>a.anchor:hover,h4:hover>a.anchor,h4>a.anchor:hover,h5:hover>a.anchor,h5>a.anchor:hover,h6:hover>a.anchor,h6>a.anchor:hover{visibility:visible}
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#content h1>a.link,h2>a.link,h3>a.link,#toctitle>a.link,.sidebarblock>.content>.title>a.link,h4>a.link,h5>a.link,h6>a.link{color:#ba3925;text-decoration:none}
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#content h1>a.link:hover,h2>a.link:hover,h3>a.link:hover,#toctitle>a.link:hover,.sidebarblock>.content>.title>a.link:hover,h4>a.link:hover,h5>a.link:hover,h6>a.link:hover{color:#a53221}
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.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
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.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{text-rendering:optimizeLegibility;text-align:left;font-family:"Noto Serif","DejaVu Serif",serif;font-size:1rem;font-style:italic}
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table.tableblock.fit-content>caption.title{white-space:nowrap;width:0}
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.paragraph.lead>p,#preamble>.sectionbody>[class="paragraph"]:first-of-type p{font-size:1.21875em;line-height:1.6;color:rgba(0,0,0,.85)}
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table.tableblock #preamble>.sectionbody>[class="paragraph"]:first-of-type p{font-size:inherit}
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.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
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.admonitionblock>table td.icon{text-align:center;width:80px}
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.admonitionblock>table td.icon img{max-width:none}
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.admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
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.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #dddddf;color:rgba(0,0,0,.6)}
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.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
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.exampleblock>.content{border-style:solid;border-width:1px;border-color:#e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;-webkit-border-radius:4px;border-radius:4px}
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.exampleblock>.content>:first-child{margin-top:0}
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.exampleblock>.content>:last-child{margin-bottom:0}
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.sidebarblock{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
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.sidebarblock>:first-child{margin-top:0}
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.sidebarblock>:last-child{margin-bottom:0}
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.sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
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.exampleblock>.content>:last-child>:last-child,.exampleblock>.content .olist>ol>li:last-child>:last-child,.exampleblock>.content .ulist>ul>li:last-child>:last-child,.exampleblock>.content .qlist>ol>li:last-child>:last-child,.sidebarblock>.content>:last-child>:last-child,.sidebarblock>.content .olist>ol>li:last-child>:last-child,.sidebarblock>.content .ulist>ul>li:last-child>:last-child,.sidebarblock>.content .qlist>ol>li:last-child>:last-child{margin-bottom:0}
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.literalblock pre,.listingblock pre:not(.highlight),.listingblock pre[class="highlight"],.listingblock pre[class^="highlight "],.listingblock pre.CodeRay,.listingblock pre.prettyprint{background:#f7f7f8}
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.sidebarblock .literalblock pre,.sidebarblock .listingblock pre:not(.highlight),.sidebarblock .listingblock pre[class="highlight"],.sidebarblock .listingblock pre[class^="highlight "],.sidebarblock .listingblock pre.CodeRay,.sidebarblock .listingblock pre.prettyprint{background:#f2f1f1}
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</head>
|
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<body class="article toc2 toc-left">
|
|
<div id="header">
|
|
<h1>Boost.System: Extensible Error Reporting</h1>
|
|
<div class="details">
|
|
<span id="author" class="author">Beman Dawes, Christopher Kohlhoff, Peter Dimov</span><br>
|
|
</div>
|
|
<div id="toc" class="toc2">
|
|
<div id="toctitle">Table of Contents</div>
|
|
<ul class="sectlevel1">
|
|
<li><a href="#introduction">Introduction</a></li>
|
|
<li><a href="#changes">Revision History</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#changes_in_boost_1_75">Changes in Boost 1.75</a></li>
|
|
<li><a href="#changes_in_boost_1_74">Changes in Boost 1.74</a></li>
|
|
<li><a href="#changes_in_boost_1_69">Changes in Boost 1.69</a></li>
|
|
<li><a href="#changes_in_boost_1_68">Changes in Boost 1.68</a></li>
|
|
<li><a href="#changes_in_boost_1_65">Changes in Boost 1.65</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#rationale">Design Rationale</a></li>
|
|
<li><a href="#reference">Reference</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#ref_use_of_c11_and_c14_features">Use of C++11 and C++14 Features</a></li>
|
|
<li><a href="#ref_macros">Macros</a></li>
|
|
<li><a href="#ref_deprecated_names">Deprecated Names</a></li>
|
|
<li><a href="#ref_boostsystemerror_code_hpp"><boost/system/error_code.hpp></a>
|
|
<ul class="sectlevel3">
|
|
<li><a href="#ref_synopsis">Synopsis</a></li>
|
|
<li><a href="#ref_class_error_category">Class error_category</a></li>
|
|
<li><a href="#ref_predefined_categories">Predefined Categories</a></li>
|
|
<li><a href="#ref_class_error_code">Class error_code</a></li>
|
|
<li><a href="#ref_class_error_condition">Class error_condition</a></li>
|
|
<li><a href="#ref_nonmember_functions">Nonmember functions</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#ref_boostsystemsystem_error_hpp"><boost/system/system_error.hpp></a>
|
|
<ul class="sectlevel3">
|
|
<li><a href="#ref_class_system_error">Class system_error</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#history">History</a></li>
|
|
<li><a href="#acknowledgments">Acknowledgments</a></li>
|
|
<li><a href="#copyright">Copyright and License</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div id="content">
|
|
<div class="sect1">
|
|
<h2 id="introduction">Introduction</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Error conditions originating from the operating system or other low-level
|
|
application program interfaces (API’s) are typically reported via an integer
|
|
representing an error code. When these low-level API calls are wrapped in
|
|
portable code, such as in a portable library, some users want to deal with the
|
|
error codes in portable ways. Other users need to get at the system specific
|
|
error codes, so they can deal with system specific needs. The Boost System
|
|
library provides simple, light-weight <code>error_code</code> objects that encapsulate
|
|
system-specific error code values, yet also provide access to more abstract
|
|
and portable error conditions via <code>error_condition</code> objects.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Because <code>error_code</code> objects can represent errors from sources other than the
|
|
operating system, including user-defined sources, each <code>error_code</code> and
|
|
<code>error_condition</code> has an associated <code>error_category</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>An exception class, <code>system_error</code>, is provided. Derived from
|
|
<code>std::runtime_error</code>, it captures the underlying <code>error_code</code> for the problem
|
|
causing the exception so that this important information is not lost.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>While exceptions are the preferred C++ default error code reporting
|
|
mechanism, users of libraries dependent on low-level API’s often need overloads
|
|
reporting error conditions via error code arguments and/or return values rather
|
|
than via throwing exceptions. Otherwise, when errors are not exceptional
|
|
occurrences and must be dealt with as they arise, programs become littered with
|
|
try/catch blocks, unreadable, and inefficient. The Boost System library
|
|
supports both error reporting by exception and by error code.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In addition to portable errors codes and conditions supported by the
|
|
<code>error_code.hpp</code> header, system-specific headers support the Cygwin, Linux,
|
|
and Windows platforms. These headers are effectively no-ops if included for
|
|
platforms other than their intended target.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Boost.System is part of the C++11 Standard Library.
|
|
A number of changes, particularly to names, were made by the C++ committee
|
|
during standardization. The Boost implementation has been tracking those changes.
|
|
See <a href="#ref_deprecated_names">Deprecated Names</a> for synonyms provided to prevent
|
|
breakage of existing user code.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="changes">Revision History</h2>
|
|
<div class="sectionbody">
|
|
<div class="sect2">
|
|
<h3 id="changes_in_boost_1_75">Changes in Boost 1.75</h3>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>The platform-specific headers <code>windows_error.hpp</code>, <code>linux_error.hpp</code>,
|
|
and <code>cygwin_error.hpp</code> emit deprecation messages and are slated for
|
|
removal.</p>
|
|
</li>
|
|
<li>
|
|
<p>The old names for <code>generic_category()</code> and <code>system_category()</code> emit
|
|
deprecation messages and are slated for removal.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>error_condition::failed</code> is deprecated and is slated for removal.
|
|
<code>operator bool()</code> for <code>error_condition</code> has been reverted to its old
|
|
meaning of <code>value() != 0</code>. This is done for compatibility with
|
|
<code>std::error_condition</code> as the next release is expected to improve
|
|
interoperability with <code><system_error></code> even further. <em>Note that this
|
|
does not affect</em> <code>error_code::failed</code>, which is still alive and well.</p>
|
|
</li>
|
|
<li>
|
|
<p>The overload of <code>error_condition::message</code> that takes a buffer is
|
|
deprecated and is slated for removal, for the same reasons. <em>Note that
|
|
this does not affect</em> <code>error_code::message</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="changes_in_boost_1_74">Changes in Boost 1.74</h3>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><code>operator bool()</code> now returns <code>failed()</code> instead of <code>value() != 0</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="changes_in_boost_1_69">Changes in Boost 1.69</h3>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>Boost.System is now header-only. A stub library is still built for
|
|
compatibility, but linking to it is no longer necessary.</p>
|
|
</li>
|
|
<li>
|
|
<p>Even more functions have been marked <code>constexpr</code>.</p>
|
|
</li>
|
|
<li>
|
|
<p>The destructor of <code>error_category</code> is now protected and no longer
|
|
virtual. This is a <em>potentially breaking change</em> but its impact
|
|
is expected to be limited.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>error_category</code> now has a constructor that accepts a 64 bit identifier,
|
|
enabling distinct category objects to compare equal.</p>
|
|
</li>
|
|
<li>
|
|
<p>The constructors of <code>error_category</code> are now protected.</p>
|
|
</li>
|
|
<li>
|
|
<p>A non-allocating, nonthrowing overload of <code>message</code> has been added.</p>
|
|
</li>
|
|
<li>
|
|
<p>A virtual function <code>failed</code> has been added, allowing categories for
|
|
which success is not synonymous with 0.</p>
|
|
</li>
|
|
<li>
|
|
<p>The deprecated <code>boost::system::throws</code> object has been removed.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>boost::throws()</code> is now deprecated and its use is discouraged.</p>
|
|
</li>
|
|
<li>
|
|
<p>The constructor of <code>system_error</code> taking a single <code>error_code</code> argument
|
|
is now explicit.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>system_error::code()</code> now returns by value.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="changes_in_boost_1_68">Changes in Boost 1.68</h3>
|
|
<div class="paragraph">
|
|
<p>On a C++14 compiler, many Boost.System functions and member functions
|
|
are now <code>constexpr</code>, and <code>error_code</code> and <code>error_condition</code> are literal
|
|
classes.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In addition to enabling use in constant expressions (and <code>constexpr</code>
|
|
functions), this significantly improves the quality of the generated code.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>As a result of this change, however, now using Boost.System from C++14
|
|
or C++17 code requires that the library be also built with C++14 or
|
|
above. This is the default on GCC 6 and newer, but not on GCC 5 or Clang.
|
|
One can build Boost for C++14 by passing the <code>cxxstd=14</code> option to <code>b2</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>(Previous versions allowed code built against any C++ standard to link
|
|
with Boost.System built against any C++ standard. In 1.68, code using
|
|
any C++ standard can link with Boost.System built with C++14 or above,
|
|
but if Boost.System is built with C++11 or below, only code also built
|
|
with C++11 and below can link to it successfully.)</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="changes_in_boost_1_65">Changes in Boost 1.65</h3>
|
|
<div class="paragraph">
|
|
<p>On a C++11 compiler, Boost.System now provides implicit conversions
|
|
from <code>boost::system::error_category</code>, <code>error_code</code>, and <code>error_condition</code>
|
|
to their standard equivalents from <code><system_error></code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This allows libraries to expose a C++11 interface and report errors
|
|
via <code>std::error_code</code> even when using Boost.System, directly or through a
|
|
dependency such as Boost.ASIO.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="rationale">Design Rationale</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p><code>error_code</code> and <code>error_condition</code> are designed as value types so
|
|
they can be copied without slicing and do not require heap allocation, but
|
|
still have polymorphic behavior based on the error category. This is achieved
|
|
by abstract base class <code>error_category</code> supplying the polymorphic behavior,
|
|
and <code>error_code</code> and <code>error_condition</code> containing a pointer to an object of a
|
|
type derived from <code>error_category</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Many of the detailed design decisions were driven by the requirements that
|
|
users to be able to add additional error categories, and that it be no more
|
|
difficult to write portable code than system-specific code.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>operator<<</code> overload for <code>error_code</code> eliminates a misleading conversion to
|
|
<code>bool</code> in code like <code>cout << ec</code>, where <code>ec</code> is of type <code>error_code</code>. It is also
|
|
useful in its own right.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="reference">Reference</h2>
|
|
<div class="sectionbody">
|
|
<div class="sect2">
|
|
<h3 id="ref_use_of_c11_and_c14_features">Use of C++11 and C++14 Features</h3>
|
|
<div class="paragraph">
|
|
<p>The library is documented to use several C++11 and C++14 features,
|
|
including <code>noexcept</code>, explicit conversion operators and <code>constexpr</code>. The
|
|
actual implementation uses C++11 and C++14 features only when they are
|
|
available, and otherwise falls back on C++03 features.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="ref_macros">Macros</h3>
|
|
<div class="paragraph">
|
|
<p>When <code>BOOST_SYSTEM_ENABLE_DEPRECATED</code> is defined, the library provides
|
|
deprecated features for compatibility. These features are bound to eventually
|
|
disappear.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>When <code>BOOST_SYSTEM_USE_UTF8</code> is defined, on Windows the library returns
|
|
UTF-8 messages using code page <code>CP_UTF8</code> instead of the default <code>CP_ACP</code>.
|
|
This macro has no effect on POSIX.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="ref_deprecated_names">Deprecated Names</h3>
|
|
<div class="paragraph">
|
|
<p>In the process of adding Boost.System to the C++11 standard library, the
|
|
C++ committee changed some names. To ease transition, Boost.System deprecates
|
|
the old names, but will provide them when the macro <code>BOOST_SYSTEM_ENABLE_DEPRECATED</code> is defined.</p>
|
|
</div>
|
|
<table class="tableblock frame-all grid-all stretch">
|
|
<colgroup>
|
|
<col style="width: 50%;">
|
|
<col style="width: 50%;">
|
|
</colgroup>
|
|
<thead>
|
|
<tr>
|
|
<th class="tableblock halign-left valign-top">Old usage, now deprecated</th>
|
|
<th class="tableblock halign-left valign-top">Replacement</th>
|
|
</tr>
|
|
</thead>
|
|
<tbody>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>get_generic_category()</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>generic_category()</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>get_system_category()</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>system_category()</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>namespace posix</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>namespace errc</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>namespace posix_error</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>namespace errc</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>get_posix_category()</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>generic_category()</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>posix_category</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>generic_category()</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>errno_ecat</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>generic_category()</code></p></td>
|
|
</tr>
|
|
<tr>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>native_ecat</code></p></td>
|
|
<td class="tableblock halign-left valign-top"><p class="tableblock"><code>system_category()</code></p></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="ref_boostsystemerror_code_hpp"><boost/system/error_code.hpp></h3>
|
|
<div class="sect3">
|
|
<h4 id="ref_synopsis">Synopsis</h4>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>namespace boost {
|
|
namespace system {
|
|
|
|
class error_category;
|
|
|
|
constexpr const error_category & system_category() noexcept;
|
|
constexpr const error_category & generic_category() noexcept;
|
|
|
|
class error_code;
|
|
class error_condition;
|
|
|
|
// "Concept" helpers
|
|
|
|
template<class T>
|
|
struct is_error_code_enum { static const bool value = false; };
|
|
|
|
template<class T>
|
|
struct is_error_condition_enum { static const bool value = false; };
|
|
|
|
// generic error conditions
|
|
|
|
namespace errc {
|
|
enum errc_t
|
|
{
|
|
success = 0,
|
|
address_family_not_supported, //EAFNOSUPPORT
|
|
address_in_use, //EADDRINUSE
|
|
address_not_available, //EADDRNOTAVAIL
|
|
already_connected, //EISCONN
|
|
argument_list_too_long, //E2BIG
|
|
argument_out_of_domain, //EDOM
|
|
bad_address, //EFAULT
|
|
bad_file_descriptor, //EBADF
|
|
bad_message, //EBADMSG
|
|
broken_pipe, //EPIPE
|
|
connection_aborted, //ECONNABORTED
|
|
connection_already_in_progress, //EALREADY
|
|
connection_refused, //ECONNREFUSED
|
|
connection_reset, //ECONNRESET
|
|
cross_device_link, //EXDEV
|
|
destination_address_required, //EDESTADDRREQ
|
|
device_or_resource_busy, //EBUSY
|
|
directory_not_empty, //ENOTEMPTY
|
|
executable_format_error, //ENOEXEC
|
|
file_exists, //EEXIST
|
|
file_too_large, //EFBIG
|
|
filename_too_long, //ENAMETOOLONG
|
|
function_not_supported, //ENOSYS
|
|
host_unreachable, //EHOSTUNREACH
|
|
identifier_removed, //EIDRM
|
|
illegal_byte_sequence, //EILSEQ
|
|
inappropriate_io_control_operation, //ENOTTY
|
|
interrupted, //EINTR
|
|
invalid_argument, //EINVAL
|
|
invalid_seek, //ESPIPE
|
|
io_error, //EIO
|
|
is_a_directory, //EISDIR
|
|
message_size, //EMSGSIZE
|
|
network_down, //ENETDOWN
|
|
network_reset, //ENETRESET
|
|
network_unreachable, //ENETUNREACH
|
|
no_buffer_space, //ENOBUFS
|
|
no_child_process, //ECHILD
|
|
no_link, //ENOLINK
|
|
no_lock_available, //ENOLCK
|
|
no_message_available, //ENODATA
|
|
no_message, //ENOMSG
|
|
no_protocol_option, //ENOPROTOOPT
|
|
no_space_on_device, //ENOSPC
|
|
no_stream_resources, //ENOSR
|
|
no_such_device_or_address, //ENXIO
|
|
no_such_device, //ENODEV
|
|
no_such_file_or_directory, //ENOENT
|
|
no_such_process, //ESRCH
|
|
not_a_directory, //ENOTDIR
|
|
not_a_socket, //ENOTSOCK
|
|
not_a_stream, //ENOSTR
|
|
not_connected, //ENOTCONN
|
|
not_enough_memory, //ENOMEM
|
|
not_supported, //ENOTSUP
|
|
operation_canceled, //ECANCELED
|
|
operation_in_progress, //EINPROGRESS
|
|
operation_not_permitted, //EPERM
|
|
operation_not_supported, //EOPNOTSUPP
|
|
operation_would_block, //EWOULDBLOCK
|
|
owner_dead, //EOWNERDEAD
|
|
permission_denied, //EACCES
|
|
protocol_error, //EPROTO
|
|
protocol_not_supported, //EPROTONOSUPPORT
|
|
read_only_file_system, //EROFS
|
|
resource_deadlock_would_occur, //EDEADLK
|
|
resource_unavailable_try_again, //EAGAIN
|
|
result_out_of_range, //ERANGE
|
|
state_not_recoverable, //ENOTRECOVERABLE
|
|
stream_timeout, //ETIME
|
|
text_file_busy, //ETXTBSY
|
|
timed_out, //ETIMEDOUT
|
|
too_many_files_open_in_system, //ENFILE
|
|
too_many_files_open, //EMFILE
|
|
too_many_links, //EMLINK
|
|
too_many_synbolic_link_levels, //ELOOP
|
|
value_too_large, //EOVERFLOW
|
|
wrong_protocol_type //EPROTOTYPE
|
|
};
|
|
|
|
} // namespace errc
|
|
|
|
template<> struct is_error_condition_enum<errc::errc_t>
|
|
{ static const bool value = true; };
|
|
|
|
// non-member functions
|
|
|
|
constexpr bool operator==( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
bool operator==( const error_code & code,
|
|
const error_condition & condition ) noexcept;
|
|
bool operator==( const error_condition & condition,
|
|
const error_code & code ) noexcept;
|
|
constexpr bool operator==( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;
|
|
|
|
constexpr bool operator!=( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
bool operator!=( const error_code & code,
|
|
const error_condition & condition ) noexcept;
|
|
bool operator!=( const error_condition & condition,
|
|
const error_code & code ) noexcept;
|
|
constexpr bool operator!=( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;
|
|
|
|
constexpr bool operator<( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
constexpr bool operator<( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;
|
|
|
|
constexpr error_code make_error_code( errc::errc_t e ) noexcept;
|
|
constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;
|
|
|
|
template <class charT, class traits>
|
|
std::basic_ostream<charT, traits>&
|
|
operator<<( basic_ostream<charT, traits>& os, const error_code & ec );
|
|
|
|
std::size_t hash_value( const error_code & ec );
|
|
|
|
} // namespace system
|
|
} // namespace boost</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The value of each <code>errc_t</code> constant is the same as the value of the <code><cerrno></code>
|
|
macro shown in the above synopsis.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Users may specialize <code>is_error_code_enum</code> and <code>is_error_condition_enum</code>
|
|
templates to indicate that a type is eligible for class <code>error_code</code> and
|
|
<code>error_condition</code> automatic conversions respectively.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="ref_class_error_category">Class error_category</h4>
|
|
<div class="paragraph">
|
|
<p>The class <code>error_category</code> defines the base class for types used
|
|
to identify the source and encoding of a particular category of error code.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Classes may be derived from <code>error_category</code> to support categories of
|
|
errors in addition to those defined in Boost.System.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>namespace boost {
|
|
namespace system {
|
|
|
|
class error_category
|
|
{
|
|
public: // noncopyable
|
|
|
|
error_category( error_category const & ) = delete;
|
|
error_category& operator=( error_category const & ) = delete;
|
|
|
|
protected:
|
|
|
|
~error_category() = default;
|
|
|
|
constexpr error_category() noexcept;
|
|
explicit constexpr error_category( unsigned long long id ) noexcept;
|
|
|
|
public:
|
|
|
|
virtual const char * name() const noexcept = 0;
|
|
|
|
virtual error_condition default_error_condition( int ev ) const noexcept;
|
|
|
|
virtual bool equivalent( int code, const error_condition & condition )
|
|
const noexcept;
|
|
virtual bool equivalent( const error_code & code, int condition )
|
|
const noexcept;
|
|
|
|
virtual std::string message( int ev ) const = 0;
|
|
virtual char const * message( int ev, char * buffer, std::size_t len )
|
|
const noexcept;
|
|
|
|
virtual bool failed( int ev ) const noexcept;
|
|
|
|
constexpr bool operator==( const error_category & rhs ) const noexcept;
|
|
constexpr bool operator!=( const error_category & rhs ) const noexcept;
|
|
constexpr bool operator< ( const error_category & rhs ) const noexcept;
|
|
|
|
operator std::error_category const & () const;
|
|
|
|
private:
|
|
|
|
unsigned long long id_; // exposition only
|
|
|
|
};
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_constructors">Constructors</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_category() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Effects: </dt>
|
|
<dd>
|
|
<p>Initializes <code>id_</code> to 0.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>Since equivalence for categories that do not have an identifier is
|
|
based on comparing object addresses, a user-defined derived category of type
|
|
<code>C</code> that uses this constructor should ensure that only one object of type <code>C</code>
|
|
exists in the program.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>explicit constexpr error_category( unsigned long long id ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Effects: </dt>
|
|
<dd>
|
|
<p>Initializes <code>id_</code> to <code>id</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>User-defined derived categories that use this constructor are considered
|
|
equivalent when their identifiers match. Therefore, those categories may have more
|
|
than one instance existing in a program, but to minimize the possibility of
|
|
collision, their identifiers must be randomly chosen (at the time the category
|
|
is implemented, not at runtime). One way of generating a 64 bit random identifier
|
|
is <a href="https://www.random.org/cgi-bin/randbyte?nbytes=8&format=h" class="bare">https://www.random.org/cgi-bin/randbyte?nbytes=8&format=h</a>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_virtuals">Virtuals</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual const char * name() const noexcept = 0;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>In derived classes, a character literal naming the error category.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual error_condition default_error_condition( int ev ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>In derived classes, an error condition corresponding to <code>ev</code>.
|
|
The returned error condition will typically come from the generic category.</p>
|
|
</li>
|
|
<li>
|
|
<p>In the default implementation, <code>error_condition( ev, *this )</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual bool equivalent( int code, const error_condition & condition )
|
|
const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>In derived classes, <code>true</code> when <code>error_code( code, *this )</code> is equivalent to <code>condition</code>.</p>
|
|
</li>
|
|
<li>
|
|
<p>In the default implementation, <code>default_error_condition( code ) == condition</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual bool equivalent( const error_code & code, int condition )
|
|
const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>In derived classes, <code>true</code> when <code>code</code> is equivalent to <code>error_condition( condition, *this )</code>.</p>
|
|
</li>
|
|
<li>
|
|
<p>In the default implementation, <code>*this == code.category() && code.value() == condition</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual std::string message( int ev ) const = 0;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>In derived classes, a string that describes the error denoted by <code>ev</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual char const * message( int ev, char * buffer, std::size_t len )
|
|
const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Effects: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>Derived classes should either</p>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>return a pointer to a character literal describing the error denoted by <code>ev</code>, or</p>
|
|
</li>
|
|
<li>
|
|
<p>copy a string describing the error into <code>buffer</code>, truncating it to <code>len-1</code>
|
|
characters and storing a null terminator, and return <code>buffer</code>. If <code>len</code> is 0,
|
|
nothing is copied, but the function still returns <code>buffer</code>. Note that
|
|
when <code>len</code> is 0, <code>buffer</code> may be <code>nullptr</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</li>
|
|
<li>
|
|
<p>The default implementation calls <code>message(ev)</code> and copies the result into
|
|
<code>buffer</code>, truncating it to <code>len-1</code> characters and storing a null terminator.
|
|
If <code>len</code> is 0, copies nothing. Returns <code>buffer</code>. If <code>message(ev)</code> throws an
|
|
exception, the string <code>"Message text unavailable"</code> is used.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Example: </dt>
|
|
<dd>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>const char* my_category::message(int ev, char* buffer, size_t len) const noexcept
|
|
{
|
|
switch(ev)
|
|
{
|
|
case 0: return "no error";
|
|
case 1: return "voltage out of range";
|
|
case 2: return "impedance mismatch";
|
|
case 31:
|
|
case 32:
|
|
case 33:
|
|
std::snprintf(buffer, len, "component %d failure", ev-30);
|
|
return buffer;
|
|
default:
|
|
std::snprintf(buffer, len, "unknown error %d", ev);
|
|
return buffer;
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>virtual bool failed( int ev ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>In derived classes, <code>true</code> when <code>ev</code> represents a failure.</p>
|
|
</li>
|
|
<li>
|
|
<p>In the default implementation, <code>ev != 0</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>All calls to this function with the same <code>ev</code> must return the same value.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_nonvirtuals">Nonvirtuals</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator==( const error_category & rhs ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>rhs.id_ == 0? this == &rhs: id_ == rhs.id_</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>Two category objects are considered equivalent when they have matching
|
|
nonzero identifiers, or are the same object.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator!=( const error_category & rhs ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>!( *this == rhs )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator< ( const error_category & rhs ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>If <code>id_ < rhs.id_</code>, <code>true</code>;</p>
|
|
</li>
|
|
<li>
|
|
<p>Otherwise, if <code>id_ > rhs.id_</code>, <code>false</code>;</p>
|
|
</li>
|
|
<li>
|
|
<p>Otherwise, if <code>rhs.id_ != 0</code>, <code>false</code>;</p>
|
|
</li>
|
|
<li>
|
|
<p>Otherwise, <code>std::less<error_category const *>()( this, &rhs )</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>operator std::error_category const & () const;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>A reference to an <code>std::error_category</code> object corresponding
|
|
to <code>*this</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="ref_predefined_categories">Predefined Categories</h4>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr const error_category & system_category() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>A reference to an <code>error_category</code> object identifying errors
|
|
originating from the operating system.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr const error_category & generic_category() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>A reference to an <code>error_category</code> object identifying portable
|
|
error conditions.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="ref_class_error_code">Class error_code</h4>
|
|
<div class="paragraph">
|
|
<p>The class <code>error_code</code> describes an object used to hold error code
|
|
values, such as those originating from the operating system or other
|
|
low-level application program interfaces. It’s an adjunct to error reporting
|
|
by exception.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>namespace boost {
|
|
namespace system {
|
|
|
|
class error_code {
|
|
public:
|
|
|
|
// constructors:
|
|
|
|
constexpr error_code() noexcept;
|
|
constexpr error_code( int val, const error_category & cat ) noexcept;
|
|
|
|
template <class ErrorCodeEnum>
|
|
constexpr error_code( ErrorCodeEnum e ) noexcept;
|
|
|
|
// modifiers:
|
|
|
|
constexpr void assign( int val, const error_category & cat ) noexcept;
|
|
|
|
template<typename ErrorCodeEnum>
|
|
constexpr error_code & operator=( ErrorCodeEnum e ) noexcept;
|
|
|
|
constexpr void clear() noexcept;
|
|
|
|
// observers:
|
|
|
|
constexpr int value() const noexcept;
|
|
constexpr const error_category & category() const noexcept;
|
|
|
|
error_condition default_error_condition() const noexcept;
|
|
|
|
std::string message() const;
|
|
char const * message( char * buffer, std::size_t len ) const noexcept;
|
|
|
|
constexpr bool failed() const noexcept;
|
|
constexpr explicit operator bool() const noexcept;
|
|
|
|
operator std::error_code() const;
|
|
|
|
private: // exposition only
|
|
|
|
int val_;
|
|
const error_category * cat_;
|
|
|
|
};
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_constructors_2">Constructors</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_code() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == 0</code>; <code>*cat_ == system_category()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_code( int val, const error_category & cat ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == val</code>; <code>cat_ == &cat</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>template <class ErrorCodeEnum>
|
|
constexpr error_code( ErrorCodeEnum e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>*this == make_error_code( e )</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>This constructor is only enabled when <code>is_error_code_enum<ErrorCodeEnum>::value</code> is <code>true</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_modifiers">Modifiers</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr void assign( int val, const error_category & cat ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == val</code>; <code>cat_ == &cat</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>template<typename ErrorCodeEnum>
|
|
constexpr error_code & operator=( ErrorCodeEnum e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>*this == make_error_code( e )</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>This operator is only enabled when <code>is_error_code_enum<ErrorCodeEnum>::value</code> is <code>true</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr void clear() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == 0</code>; <code>*cat_ == system_category()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_observers">Observers</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr int value() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>val_</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr const error_category & category() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>*cat_</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>error_condition default_error_condition() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->default_error_condition( val_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>std::string message() const;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->message( val_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>char const * message( char * buffer, std::size_t len ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->message( val_, buffer, len )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool failed() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->failed( val_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr explicit operator bool() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>failed()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>operator std::error_code() const;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>std::error_code( val_, *cat_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="ref_class_error_condition">Class error_condition</h4>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>namespace boost {
|
|
namespace system {
|
|
|
|
class error_condition {
|
|
public:
|
|
|
|
// constructors:
|
|
|
|
constexpr error_condition() noexcept;
|
|
constexpr error_condition( int val, const error_category & cat ) noexcept;
|
|
|
|
template <class ErrorConditionEnum>
|
|
constexpr error_condition( ErrorConditionEnum e ) noexcept;
|
|
|
|
// modifiers:
|
|
|
|
constexpr void assign( int val, const error_category & cat ) noexcept;
|
|
|
|
template<typename ErrorConditionEnum>
|
|
constexpr error_condition & operator=( ErrorConditionEnum e ) noexcept;
|
|
|
|
constexpr void clear() noexcept;
|
|
|
|
// observers:
|
|
|
|
constexpr int value() const noexcept;
|
|
constexpr const error_category & category() const noexcept;
|
|
|
|
std::string message() const;
|
|
|
|
constexpr explicit operator bool() const noexcept;
|
|
|
|
operator std::error_condition() const;
|
|
|
|
// deprecated members; do not use
|
|
|
|
char const * message( char * buffer, std::size_t len ) const noexcept;
|
|
constexpr bool failed() const noexcept;
|
|
|
|
private: // exposition only
|
|
|
|
int val_;
|
|
const error_category * cat_;
|
|
|
|
};
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_constructors_3">Constructors</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_condition() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == 0</code>; <code>*cat_ == generic_category()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_condition( int val, const error_category & cat ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == val</code>; <code>cat_ == &cat</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>template <class ErrorConditionEnum>
|
|
constexpr error_condition( ErrorConditionEnum e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>*this == make_error_condition( e )</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>This constructor is only enabled when <code>is_error_condition_enum<ErrorConditionEnum>::value</code> is <code>true</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_modifiers_2">Modifiers</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr void assign( int val, const error_category & cat ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == val</code>; <code>cat_ == &cat</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>template <class ErrorConditionEnum>
|
|
constexpr error_condition & operator=( ErrorConditionEnum e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>*this == make_error_condition( e )</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Remarks: </dt>
|
|
<dd>
|
|
<p>This operator is only enabled when <code>is_error_condition_enum<ErrorConditionEnum>::value</code> is <code>true</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr void clear() noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>val_ == 0</code>; <code>*cat_ == generic_category()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_observers_2">Observers</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr int value() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>val_</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr const error_category & category() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>*cat_</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>std::string message() const;</code></pre>
|
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</div>
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</div>
|
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<div class="ulist none">
|
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<ul class="none">
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<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->message( val_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr explicit operator bool() const noexcept;</code></pre>
|
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</div>
|
|
</div>
|
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<div class="ulist none">
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<ul class="none">
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<li>
|
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<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
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<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>value() != 0</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>operator std::error_condition() const;</code></pre>
|
|
</div>
|
|
</div>
|
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<div class="ulist none">
|
|
<ul class="none">
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<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>std::error_condition( val_, *cat_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_deprecated_members">Deprecated members</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>char const * message( char * buffer, std::size_t len ) const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->message( val_, buffer, len )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="admonitionblock warning">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Warning</div>
|
|
</td>
|
|
<td class="content">
|
|
This member function is deprecated and will be removed. This is done
|
|
for compatibility with <code>std::error_condition</code> as the next release is
|
|
expected to improve interoperability with <code><system_error></code> even further.
|
|
<em>Note that this does not affect</em> <code>error_code::message</code>.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool failed() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>cat_->failed( val_ )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="admonitionblock warning">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Warning</div>
|
|
</td>
|
|
<td class="content">
|
|
This member function is deprecated and will be removed. This is done
|
|
for compatibility with <code>std::error_condition</code> as the next release is
|
|
expected to improve interoperability with <code><system_error></code> even further.
|
|
<em>Note that this does not affect</em> <code>error_code::failed</code>.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="ref_nonmember_functions">Nonmember functions</h4>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator==( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
constexpr bool operator==( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>lhs.value() == rhs.value() && lhs.category() == rhs.category()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>bool operator==( const error_code & code,
|
|
const error_condition & condition ) noexcept;
|
|
bool operator==( const error_condition & condition,
|
|
const error_code & code ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator!=( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
constexpr bool operator!=( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;
|
|
bool operator!=( const error_code & code,
|
|
const error_condition & condition ) noexcept;
|
|
bool operator!=( const error_condition & condition,
|
|
const error_code & code ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>!( lhs == rhs )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr bool operator<( const error_code & lhs,
|
|
const error_code & rhs ) noexcept;
|
|
constexpr bool operator<( const error_condition & lhs,
|
|
const error_condition & rhs ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>lhs.category() < rhs.category() || ( lhs.category() == rhs.category() && lhs.value() < rhs.value() )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_code make_error_code( errc::errc_t e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>error_code( e, generic_category() )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>error_condition( e, generic_category() )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>template <class charT, class traits>
|
|
std::basic_ostream<charT, traits>&
|
|
operator<<( basic_ostream<charT, traits>& os, const error_code & ec );</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Effects: </dt>
|
|
<dd>
|
|
<p><code>os << ec.category().name() << ':' << ec.value()</code>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>os</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>std::size_t hash_value( const error_code & ec );</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>A hash value representing <code>ec</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="ref_boostsystemsystem_error_hpp"><boost/system/system_error.hpp></h3>
|
|
<div class="sect3">
|
|
<h4 id="ref_class_system_error">Class system_error</h4>
|
|
<div class="paragraph">
|
|
<p>The class <code>system_error</code> describes an exception object used to
|
|
report errors that have an associated <code>error_code</code>. Such errors
|
|
typically originate from operating system or other low-level
|
|
application program interfaces.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>namespace boost
|
|
{
|
|
namespace system
|
|
{
|
|
class system_error: public std::runtime_error
|
|
{
|
|
public:
|
|
|
|
explicit system_error( error_code ec );
|
|
system_error( error_code ec, const char * what_arg );
|
|
system_error( error_code ec, const std::string & what_arg );
|
|
|
|
system_error( int ev, const error_category & ecat );
|
|
system_error( int ev, const error_category & ecat,
|
|
const char * what_arg );
|
|
system_error( int ev, const error_category & ecat,
|
|
const std::string & what_arg );
|
|
|
|
error_code code() const noexcept;
|
|
const char * what() const noexcept;
|
|
};
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_constructors_4">Constructors</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>explicit system_error( error_code ec );
|
|
system_error( error_code ec, const char * what_arg );
|
|
system_error( error_code ec, const std::string & what_arg );</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>code() == ec</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>system_error( int ev, const error_category & ecat,
|
|
const char * what_arg );
|
|
system_error( int ev, const error_category & ecat,
|
|
const std::string & what_arg );
|
|
system_error( int ev, const error_category & ecat );</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Ensures: </dt>
|
|
<dd>
|
|
<p><code>code() == error_code( ev, ecat )</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect4">
|
|
<h5 id="ref_observers_3">Observers</h5>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>error_code code() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p><code>ec</code> or <code>error_code( ev, ecat )</code>, from the constructor, as appropriate.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>const char * what() const noexcept;</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="ulist none">
|
|
<ul class="none">
|
|
<li>
|
|
<p></p>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Returns: </dt>
|
|
<dd>
|
|
<p>A null-terminated character string incorporating the arguments supplied
|
|
in the constructor, typically of the form <code>what_arg + ": " + code.message()</code>.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="history">History</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1975.html">N1975</a>,
|
|
Filesystem Library Proposal for TR2, accepted for Library Technical
|
|
Report 2 (TR2) at the Berlin meeting, included additional components to
|
|
supplement the Standard Library’s Diagnostics clause. Since then, these error
|
|
reporting components have received wider public scrutiny and enhancements have
|
|
been made to the design. The enhanced version has been used by
|
|
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2054.pdf">N2054</a>,
|
|
Networking Library Proposal for TR2, demonstrating that these error reporting
|
|
components are useful beyond the original Filesystem Library.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The original proposal viewed error categories as a binary choice between
|
|
<code>errno</code> (i.e. POSIX-style) and the native operating system’s error
|
|
codes. The proposed components now allow as many additional error categories as
|
|
are needed by either implementations or by users. The need to support additional
|
|
error categories, for example, occurs in some networking library implementations
|
|
because they are built on top of the POSIX <code>getaddrinfo</code> API that
|
|
uses error codes not based on <code>errno</code>.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="acknowledgments">Acknowledgments</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Christopher Kohlhoff and Peter Dimov made important contributions to the
|
|
design. Comments and suggestions were also received from Pavel Vozenilek,
|
|
Gennaro Prota, Dave Abrahams, Jeff Garland, Iain Hanson, Oliver Kowalke, and
|
|
Oleg Abrosimov. Christopher Kohlhoff suggested several improvements to the
|
|
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2066.html">N2066</a>
|
|
paper. Johan Nilsson’s comments led to several of the refinements in N2066.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="copyright">Copyright and License</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>This documentation is</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>Copyright 2003-2017 Beman Dawes</p>
|
|
</li>
|
|
<li>
|
|
<p>Copyright 2018 Peter Dimov</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>and is distributed under the <a href="http://www.boost.org/LICENSE_1_0.txt">Boost Software License, Version 1.0</a>.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div id="footer">
|
|
<div id="footer-text">
|
|
Last updated 2021-04-13 16:23:05 UTC
|
|
</div>
|
|
</div>
|
|
<style>
|
|
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*:not(pre)>code { background: none; color: #600000; }
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:not(pre):not([class^=L])>code { background: none; color: #600000; }
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</style>
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</body>
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</html> |