// -*- C++ -*-
//===--------------------------- regex ------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_REGEX
#define _LIBCPP_REGEX

/*
    regex synopsis

#include <initializer_list>

namespace std
{

namespace regex_constants
{

emum syntax_option_type
{
    icase      = unspecified,
    nosubs     = unspecified,
    optimize   = unspecified,
    collate    = unspecified,
    ECMAScript = unspecified,
    basic      = unspecified,
    extended   = unspecified,
    awk        = unspecified,
    grep       = unspecified,
    egrep      = unspecified
};

constexpr syntax_option_type operator~(syntax_option_type f);
constexpr syntax_option_type operator&(syntax_option_type lhs, syntax_option_type rhs);
constexpr syntax_option_type operator|(syntax_option_type lhs, syntax_option_type rhs);

enum match_flag_type
{
    match_default     = 0,
    match_not_bol     = unspecified,
    match_not_eol     = unspecified,
    match_not_bow     = unspecified,
    match_not_eow     = unspecified,
    match_any         = unspecified,
    match_not_null    = unspecified,
    match_continuous  = unspecified,
    match_prev_avail  = unspecified,
    format_default    = 0,
    format_sed        = unspecified,
    format_no_copy    = unspecified,
    format_first_only = unspecified
};

constexpr match_flag_type operator~(match_flag_type f);
constexpr match_flag_type operator&(match_flag_type lhs, match_flag_type rhs);
constexpr match_flag_type operator|(match_flag_type lhs, match_flag_type rhs);

enum error_type
{
    error_collate    = unspecified,
    error_ctype      = unspecified,
    error_escape     = unspecified,
    error_backref    = unspecified,
    error_brack      = unspecified,
    error_paren      = unspecified,
    error_brace      = unspecified,
    error_badbrace   = unspecified,
    error_range      = unspecified,
    error_space      = unspecified,
    error_badrepeat  = unspecified,
    error_complexity = unspecified,
    error_stack      = unspecified
};

}  // regex_constants

class regex_error
    : public runtime_error
{
public:
    explicit regex_error(regex_constants::error_type ecode);
    regex_constants::error_type code() const;
};

template <class charT>
struct regex_traits
{
public:
    typedef charT                   char_type;
    typedef basic_string<char_type> string_type;
    typedef locale                  locale_type;
    typedef /bitmask_type/          char_class_type;

    regex_traits();

    static size_t length(const char_type* p);
    charT translate(charT c) const;
    charT translate_nocase(charT c) const;
    template <class ForwardIterator>
        string_type
        transform(ForwardIterator first, ForwardIterator last) const;
    template <class ForwardIterator>
        string_type
        transform_primary( ForwardIterator first, ForwardIterator last) const;
    template <class ForwardIterator>
        string_type
        lookup_collatename(ForwardIterator first, ForwardIterator last) const;
    template <class ForwardIterator>
        char_class_type
        lookup_classname(ForwardIterator first, ForwardIterator last,
                         bool icase = false) const;
    bool isctype(charT c, char_class_type f) const;
    int value(charT ch, int radix) const;
    locale_type imbue(locale_type l);
    locale_type getloc()const;
};

template <class charT, class traits = regex_traits<charT>>
class basic_regex
{
public:
    // types:
    typedef charT                               value_type;
    typedef regex_constants::syntax_option_type flag_type;
    typedef typename traits::locale_type        locale_type;

    // constants:
    static constexpr regex_constants::syntax_option_type icase = regex_constants::icase;
    static constexpr regex_constants::syntax_option_type nosubs = regex_constants::nosubs;
    static constexpr regex_constants::syntax_option_type optimize = regex_constants::optimize;
    static constexpr regex_constants::syntax_option_type collate = regex_constants::collate;
    static constexpr regex_constants::syntax_option_type ECMAScript = regex_constants::ECMAScript;
    static constexpr regex_constants::syntax_option_type basic = regex_constants::basic;
    static constexpr regex_constants::syntax_option_type extended = regex_constants::extended;
    static constexpr regex_constants::syntax_option_type awk = regex_constants::awk;
    static constexpr regex_constants::syntax_option_type grep = regex_constants::grep;
    static constexpr regex_constants::syntax_option_type egrep = regex_constants::egrep;

    // construct/copy/destroy:
    basic_regex();
    explicit basic_regex(const charT* p, flag_type f = regex_constants::ECMAScript);
    basic_regex(const charT* p, size_t len, flag_type f);
    basic_regex(const basic_regex&);
    basic_regex(basic_regex&&);
    template <class ST, class SA>
        explicit basic_regex(const basic_string<charT, ST, SA>& p,
                             flag_type f = regex_constants::ECMAScript);
    template <class ForwardIterator>
        basic_regex(ForwardIterator first, ForwardIterator last,
                    flag_type f = regex_constants::ECMAScript);
    basic_regex(initializer_list<charT>, flag_type = regex_constants::ECMAScript);

    ~basic_regex();

    basic_regex& operator=(const basic_regex&);
    basic_regex& operator=(basic_regex&&);
    basic_regex& operator=(const charT* ptr);
    basic_regex& operator=(initializer_list<charT> il);
    template <class ST, class SA>
        basic_regex& operator=(const basic_string<charT, ST, SA>& p);

    // assign:
    basic_regex& assign(const basic_regex& that);
    basic_regex& assign(basic_regex&& that);
    basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript);
    basic_regex& assign(const charT* p, size_t len, flag_type f);
    template <class string_traits, class A>
        basic_regex& assign(const basic_string<charT, string_traits, A>& s,
                            flag_type f = regex_constants::ECMAScript);
    template <class InputIterator>
        basic_regex& assign(InputIterator first, InputIterator last,
                            flag_type f = regex_constants::ECMAScript);
    basic_regex& assign(initializer_list<charT>, flag_type = regex_constants::ECMAScript);

    // const operations:
    unsigned mark_count() const;
    flag_type flags() const;

    // locale:
    locale_type imbue(locale_type loc);
    locale_type getloc() const;

    // swap:
    void swap(basic_regex&);
};

typedef basic_regex<char>    regex;
typedef basic_regex<wchar_t> wregex;

template <class charT, class traits>
    void swap(basic_regex<charT, traits>& e1, basic_regex<charT, traits>& e2);

template <class BidirectionalIterator>
class sub_match
    : public pair<BidirectionalIterator, BidirectionalIterator>
{
public:
    typedef typename iterator_traits<BidirectionalIterator>::value_type value_type;
    typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
    typedef BidirectionalIterator                                      iterator;
    typedef basic_string<value_type>                                string_type;

    bool matched;

    difference_type length() const;
    operator string_type() const;
    string_type str() const;

    int compare(const sub_match& s) const;
    int compare(const string_type& s) const;
    int compare(const value_type* s) const;
};

typedef sub_match<const char*>             csub_match;
typedef sub_match<const wchar_t*>          wcsub_match;
typedef sub_match<string::const_iterator>  ssub_match;
typedef sub_match<wstring::const_iterator> wssub_match;

template <class BiIter>
    bool
    operator==(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator!=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator==(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator!=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator<(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator>(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool operator>=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
                    const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator<=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator==(const sub_match<BiIter>& lhs,
               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator!=(const sub_match<BiIter>& lhs,
               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator<(const sub_match<BiIter>& lhs,
              const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter, class ST, class SA>
    bool operator>(const sub_match<BiIter>& lhs,
                   const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator>=(const sub_match<BiIter>& lhs,
               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter, class ST, class SA>
    bool
    operator<=(const sub_match<BiIter>& lhs,
               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);

template <class BiIter>
    bool
    operator==(typename iterator_traits<BiIter>::value_type const* lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator!=(typename iterator_traits<BiIter>::value_type const* lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<(typename iterator_traits<BiIter>::value_type const* lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>(typename iterator_traits<BiIter>::value_type const* lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>=(typename iterator_traits<BiIter>::value_type const* lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<=(typename iterator_traits<BiIter>::value_type const* lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator==(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator!=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator<(const sub_match<BiIter>& lhs,
              typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator>(const sub_match<BiIter>& lhs,
              typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator>=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator<=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const* rhs);

template <class BiIter>
    bool
    operator==(typename iterator_traits<BiIter>::value_type const& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator!=(typename iterator_traits<BiIter>::value_type const& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<(typename iterator_traits<BiIter>::value_type const& lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>(typename iterator_traits<BiIter>::value_type const& lhs,
              const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator>=(typename iterator_traits<BiIter>::value_type const& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator<=(typename iterator_traits<BiIter>::value_type const& lhs,
               const sub_match<BiIter>& rhs);

template <class BiIter>
    bool
    operator==(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const& rhs);

template <class BiIter>
    bool
    operator!=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const& rhs);

template <class BiIter>
    bool
    operator<(const sub_match<BiIter>& lhs,
              typename iterator_traits<BiIter>::value_type const& rhs);

template <class BiIter>
    bool
    operator>(const sub_match<BiIter>& lhs,
              typename iterator_traits<BiIter>::value_type const& rhs);

template <class BiIter>
    bool
    operator>=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const& rhs);

template <class BiIter>
    bool
    operator<=(const sub_match<BiIter>& lhs,
               typename iterator_traits<BiIter>::value_type const& rhs);

template <class charT, class ST, class BiIter>
    basic_ostream<charT, ST>&
    operator<<(basic_ostream<charT, ST>& os, const sub_match<BiIter>& m);

template <class BidirectionalIterator,
          class Allocator = allocator<sub_match<BidirectionalIterator>>>
class match_results
{
public:
    typedef sub_match<BidirectionalIterator>                  value_type;
    typedef const value_type&                                 const_reference;
    typedef const_reference                                   reference;
    typedef /implementation-defined/                          const_iterator;
    typedef const_iterator                                    iterator;
    typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
    typedef typename allocator_traits<Allocator>::size_type   size_type;
    typedef Allocator                                         allocator_type;
    typedef typename iterator_traits<BidirectionalIterator>::value_type char_type;
    typedef basic_string<char_type>                           string_type;

    // construct/copy/destroy:
    explicit match_results(const Allocator& a = Allocator());
    match_results(const match_results& m);
    match_results(match_results&& m);
    match_results& operator=(const match_results& m);
    match_results& operator=(match_results&& m);
    ~match_results();

    // size:
    size_type size() const;
    size_type max_size() const;
    bool empty() const;

    // element access:
    difference_type length(size_type sub = 0) const;
    difference_type position(size_type sub = 0) const;
    string_type str(size_type sub = 0) const;
    const_reference operator[](size_type n) const;

    const_reference prefix() const;
    const_reference suffix() const;

    const_iterator begin() const;
    const_iterator end() const;
    const_iterator cbegin() const;
    const_iterator cend() const;

    // format:
    template <class OutputIter>
        OutputIter
        format(OutputIter out, const char_type* fmt_first,
               const char_type* fmt_last,
               regex_constants::match_flag_type flags = regex_constants::format_default) const;
    template <class OutputIter, class ST, class SA>
        OutputIter
        format(OutputIter out, const basic_string<char_type, ST, SA>& fmt,
               regex_constants::match_flag_type flags = regex_constants::format_default) const;
    template <class ST, class SA>
        basic_string<char_type, ST, SA>
        format(const basic_string<char_type, ST, SA>& fmt,
               regex_constants::match_flag_type flags = regex_constants::format_default) const;
    string_type
        format(const char_type* fmt,
               regex_constants::match_flag_type flags = regex_constants::format_default) const;

    // allocator:
    allocator_type get_allocator() const;

    // swap:
    void swap(match_results& that);
};

typedef match_results<const char*>             cmatch;
typedef match_results<const wchar_t*>          wcmatch;
typedef match_results<string::const_iterator>  smatch;
typedef match_results<wstring::const_iterator> wsmatch;

template <class BidirectionalIterator, class Allocator>
    bool
    operator==(const match_results<BidirectionalIterator, Allocator>& m1,
               const match_results<BidirectionalIterator, Allocator>& m2);

template <class BidirectionalIterator, class Allocator>
    bool
    operator!=(const match_results<BidirectionalIterator, Allocator>& m1,
               const match_results<BidirectionalIterator, Allocator>& m2);

template <class BidirectionalIterator, class Allocator>
    void
    swap(match_results<BidirectionalIterator, Allocator>& m1,
         match_results<BidirectionalIterator, Allocator>& m2);

template <class BidirectionalIterator, class Allocator, class charT, class traits>
    bool
    regex_match(BidirectionalIterator first, BidirectionalIterator last,
                match_results<BidirectionalIterator, Allocator>& m,
                const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class BidirectionalIterator, class charT, class traits>
    bool
    regex_match(BidirectionalIterator first, BidirectionalIterator last,
                const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class charT, class Allocator, class traits>
    bool
    regex_match(const charT* str, match_results<const charT*, Allocator>& m,
                const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class ST, class SA, class Allocator, class charT, class traits>
    bool
    regex_match(const basic_string<charT, ST, SA>& s,
                match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
                const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class charT, class traits>
    bool
    regex_match(const charT* str, const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class ST, class SA, class charT, class traits>
    bool
    regex_match(const basic_string<charT, ST, SA>& s,
                const basic_regex<charT, traits>& e,
                regex_constants::match_flag_type flags = regex_constants::match_default);

template <class BidirectionalIterator, class Allocator, class charT, class traits>
    bool
    regex_search(BidirectionalIterator first, BidirectionalIterator last,
                 match_results<BidirectionalIterator, Allocator>& m,
                 const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class BidirectionalIterator, class charT, class traits>
    bool
    regex_search(BidirectionalIterator first, BidirectionalIterator last,
                 const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class charT, class Allocator, class traits>
    bool
    regex_search(const charT* str, match_results<const charT*, Allocator>& m,
                 const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class charT, class traits>
    bool
    regex_search(const charT* str, const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class ST, class SA, class charT, class traits>
    bool
    regex_search(const basic_string<charT, ST, SA>& s,
                 const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class ST, class SA, class Allocator, class charT, class traits>
    bool
    regex_search(const basic_string<charT, ST, SA>& s,
                 match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
                 const basic_regex<charT, traits>& e,
                 regex_constants::match_flag_type flags = regex_constants::match_default);

template <class OutputIterator, class BidirectionalIterator,
          class traits, class charT, class ST, class SA>
    OutputIterator
    regex_replace(OutputIterator out,
                  BidirectionalIterator first, BidirectionalIterator last,
                  const basic_regex<charT, traits>& e,
                  const basic_string<charT, ST, SA>& fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class OutputIterator, class BidirectionalIterator,
          class traits, class charT>
    OutputIterator
    regex_replace(OutputIterator out,
                  BidirectionalIterator first, BidirectionalIterator last,
                  const basic_regex<charT, traits>& e, const charT* fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class traits, class charT, class ST, class SA, class FST, class FSA>>
    basic_string<charT, ST, SA>
    regex_replace(const basic_string<charT, ST, SA>& s,
                  const basic_regex<charT, traits>& e,
                  const basic_string<charT, FST, FSA>& fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class traits, class charT, class ST, class SA>
    basic_string<charT, ST, SA>
    regex_replace(const basic_string<charT, ST, SA>& s,
                  const basic_regex<charT, traits>& e, const charT* fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class traits, class charT, class ST, class SA>
    basic_string<charT>
    regex_replace(const charT* s,
                  const basic_regex<charT, traits>& e,
                  const basic_string<charT, ST, SA>& fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class traits, class charT>
    basic_string<charT>
    regex_replace(const charT* s,
                  const basic_regex<charT, traits>& e,
                  const charT* fmt,
                  regex_constants::match_flag_type flags = regex_constants::match_default);

template <class BidirectionalIterator,
          class charT = typename iterator_traits< BidirectionalIterator>::value_type,
          class traits = regex_traits<charT>>
class regex_iterator
{
public:
    typedef basic_regex<charT, traits>           regex_type;
    typedef match_results<BidirectionalIterator> value_type;
    typedef ptrdiff_t                            difference_type;
    typedef const value_type*                    pointer;
    typedef const value_type&                    reference;
    typedef forward_iterator_tag                 iterator_category;

    regex_iterator();
    regex_iterator(BidirectionalIterator a, BidirectionalIterator b,
                   const regex_type& re,
                   regex_constants::match_flag_type m = regex_constants::match_default);
    regex_iterator(const regex_iterator&);
    regex_iterator& operator=(const regex_iterator&);

    bool operator==(const regex_iterator&) const;
    bool operator!=(const regex_iterator&) const;

    const value_type& operator*() const;
    const value_type* operator->() const;

    regex_iterator& operator++();
    regex_iterator operator++(int);
};

typedef regex_iterator<const char*>             cregex_iterator;
typedef regex_iterator<const wchar_t*>          wcregex_iterator;
typedef regex_iterator<string::const_iterator>  sregex_iterator;
typedef regex_iterator<wstring::const_iterator> wsregex_iterator;

template <class BidirectionalIterator,
          class charT = typename iterator_traits< BidirectionalIterator>::value_type,
          class traits = regex_traits<charT>>
class regex_token_iterator
{
public:
    typedef basic_regex<charT, traits>       regex_type;
    typedef sub_match<BidirectionalIterator> value_type;
    typedef ptrdiff_t                        difference_type;
    typedef const value_type*                pointer;
    typedef const value_type&                reference;
    typedef forward_iterator_tag             iterator_category;

    regex_token_iterator();
    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
                         const regex_type& re, int submatch = 0,
                         regex_constants::match_flag_type m = regex_constants::match_default);
    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
                         const regex_type& re, const vector<int>& submatches,
                         regex_constants::match_flag_type m = regex_constants::match_default);
    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
                         const regex_type& re, initializer_list<int> submatches,
                         regex_constants::match_flag_type m = regex_constants::match_default);
    template <size_t N>
        regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
                             const regex_type& re, const int (&submatches)[N],
                             regex_constants::match_flag_type m = regex_constants::match_default);
    regex_token_iterator(const regex_token_iterator&);
    regex_token_iterator& operator=(const regex_token_iterator&);

    bool operator==(const regex_token_iterator&) const;
    bool operator!=(const regex_token_iterator&) const;

    const value_type& operator*() const;
    const value_type* operator->() const;

    regex_token_iterator& operator++();
    regex_token_iterator operator++(int);
};

typedef regex_token_iterator<const char*>             cregex_token_iterator;
typedef regex_token_iterator<const wchar_t*>          wcregex_token_iterator;
typedef regex_token_iterator<string::const_iterator>  sregex_token_iterator;
typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;

} // std
*/

#include <__config>
#include <stdexcept>
#include <__locale>

#pragma GCC system_header

_LIBCPP_BEGIN_NAMESPACE_STD

namespace regex_constants
{

// syntax_option_type

enum syntax_option_type
{
    icase      = 1 << 0,
    nosubs     = 1 << 1,
    optimize   = 1 << 2,
    collate    = 1 << 3,
    ECMAScript = 1 << 4,
    basic      = 1 << 5,
    extended   = 1 << 6,
    awk        = 1 << 7,
    grep       = 1 << 8,
    egrep      = 1 << 9
};

inline
/*constexpr*/
syntax_option_type
operator~(syntax_option_type __x)
{
    return syntax_option_type(~int(__x));
}

inline
/*constexpr*/
syntax_option_type
operator&(syntax_option_type __x, syntax_option_type __y)
{
    return syntax_option_type(int(__x) & int(__y));
}

inline
/*constexpr*/
syntax_option_type
operator|(syntax_option_type __x, syntax_option_type __y)
{
    return syntax_option_type(int(__x) | int(__y));
}

inline
/*constexpr*/
syntax_option_type
operator^(syntax_option_type __x, syntax_option_type __y)
{
    return syntax_option_type(int(__x) ^ int(__y));
}

inline
/*constexpr*/
syntax_option_type&
operator&=(syntax_option_type& __x, syntax_option_type __y)
{
    __x = __x & __y;
    return __x;
}

inline
/*constexpr*/
syntax_option_type&
operator|=(syntax_option_type& __x, syntax_option_type __y)
{
    __x = __x | __y;
    return __x;
}

inline
/*constexpr*/
syntax_option_type&
operator^=(syntax_option_type& __x, syntax_option_type __y)
{
    __x = __x ^ __y;
    return __x;
}

// match_flag_type

enum match_flag_type
{
    match_default     = 0,
    match_not_bol     = 1 << 0,
    match_not_eol     = 1 << 1,
    match_not_bow     = 1 << 2,
    match_not_eow     = 1 << 3,
    match_any         = 1 << 4,
    match_not_null    = 1 << 5,
    match_continuous  = 1 << 6,
    match_prev_avail  = 1 << 7,
    format_default    = 0,
    format_sed        = 1 << 8,
    format_no_copy    = 1 << 9,
    format_first_only = 1 << 10
};

inline
/*constexpr*/
match_flag_type
operator~(match_flag_type __x)
{
    return match_flag_type(~int(__x));
}

inline
/*constexpr*/
match_flag_type
operator&(match_flag_type __x, match_flag_type __y)
{
    return match_flag_type(int(__x) & int(__y));
}

inline
/*constexpr*/
match_flag_type
operator|(match_flag_type __x, match_flag_type __y)
{
    return match_flag_type(int(__x) | int(__y));
}

inline
/*constexpr*/
match_flag_type
operator^(match_flag_type __x, match_flag_type __y)
{
    return match_flag_type(int(__x) ^ int(__y));
}

inline
/*constexpr*/
match_flag_type&
operator&=(match_flag_type& __x, match_flag_type __y)
{
    __x = __x & __y;
    return __x;
}

inline
/*constexpr*/
match_flag_type&
operator|=(match_flag_type& __x, match_flag_type __y)
{
    __x = __x | __y;
    return __x;
}

inline
/*constexpr*/
match_flag_type&
operator^=(match_flag_type& __x, match_flag_type __y)
{
    __x = __x ^ __y;
    return __x;
}

enum error_type
{
    error_collate = 1,
    error_ctype,
    error_escape,
    error_backref,
    error_brack,
    error_paren,
    error_brace,
    error_badbrace,
    error_range,
    error_space,
    error_badrepeat,
    error_complexity,
    error_stack
};

}  // regex_constants

class _LIBCPP_EXCEPTION_ABI regex_error
    : public runtime_error
{
    regex_constants::error_type __code_;
public:
    explicit regex_error(regex_constants::error_type __ecode);
    virtual ~regex_error() throw();
    regex_constants::error_type code() const {return __code_;}
};

template <class _CharT>
struct regex_traits
{
public:
    typedef _CharT                  char_type;
    typedef basic_string<char_type> string_type;
    typedef locale                  locale_type;
    typedef unsigned                char_class_type;

private:
    locale __loc_;
    const ctype<char_type>* __ct_;
    const collate<char_type>* __col_;

public:
    regex_traits();

    static size_t length(const char_type* __p)
        {return char_traits<char_type>::length(__p);}
    char_type translate(char_type __c) const {return __c;}
    char_type translate_nocase(char_type __c) const;
    template <class _ForwardIterator>
        string_type
        transform(_ForwardIterator __f, _ForwardIterator __l) const;
    template <class _ForwardIterator>
        string_type
        transform_primary( _ForwardIterator __f, _ForwardIterator __l) const
            {return __transform_primary(__f, __l, char_type());}
    template <class _ForwardIterator>
        string_type
        lookup_collatename(_ForwardIterator __f, _ForwardIterator __l) const
            {return __lookup_collatename(__f, __l, char_type());}
    template <class _ForwardIterator>
        char_class_type
        lookup_classname(_ForwardIterator __f, _ForwardIterator __l,
                         bool __icase = false) const;
    bool isctype(char_type __c, char_class_type __f) const;
    int value(char_type __ch, int __radix) const;
    locale_type imbue(locale_type __l);
    locale_type getloc()const {return __loc_;}

private:
    void __init();

    template <class _ForwardIterator>
        string_type
        __transform_primary(_ForwardIterator __f, _ForwardIterator __l, char) const;
    template <class _ForwardIterator>
        string_type
        __transform_primary(_ForwardIterator __f, _ForwardIterator __l, wchar_t) const;

    template <class _ForwardIterator>
        string_type
        __lookup_collatename(_ForwardIterator __f, _ForwardIterator __l, char) const;
    template <class _ForwardIterator>
        string_type
        __lookup_collatename(_ForwardIterator __f, _ForwardIterator __l, wchar_t) const;
};

template <class _CharT>
regex_traits<_CharT>::regex_traits()
{
    __init();
}

template <class _CharT>
typename regex_traits<_CharT>::char_type
regex_traits<_CharT>::translate_nocase(char_type __c) const
{
    return __ct_->tolower(__c);
}

template <class _CharT>
template <class _ForwardIterator>
typename regex_traits<_CharT>::string_type
regex_traits<_CharT>::transform(_ForwardIterator __f, _ForwardIterator __l) const
{
    string_type __s(__f, __l);
    return __col_->transform(__s.data(), __s.data() + __s.size());
}

template <class _CharT>
void
regex_traits<_CharT>::__init()
{
    __ct_ = &use_facet<ctype<char_type> >(__loc_);
    __col_ = &use_facet<collate<char_type> >(__loc_);
}

template <class _CharT>
typename regex_traits<_CharT>::locale_type
regex_traits<_CharT>::imbue(locale_type __l)
{
    locale __r = __loc_;
    __loc_ = __l;
    __init();
    return __r;
}

// transform_primary is very FreeBSD-specific

template <class _CharT>
template <class _ForwardIterator>
typename regex_traits<_CharT>::string_type
regex_traits<_CharT>::__transform_primary(_ForwardIterator __f,
                                          _ForwardIterator __l, char) const
{
    const string_type __s(__f, __l);
    string_type __d = __col_->transform(__s.data(), __s.data() + __s.size());
    switch (__d.size())
    {
    case 1:
        break;
    case 12:
        __d[11] = __d[3];
        break;
    default:
        __d.clear();
        break;
    }
    return __d;
}

template <class _CharT>
template <class _ForwardIterator>
typename regex_traits<_CharT>::string_type
regex_traits<_CharT>::__transform_primary(_ForwardIterator __f,
                                          _ForwardIterator __l, wchar_t) const
{
    const string_type __s(__f, __l);
    string_type __d = __col_->transform(__s.data(), __s.data() + __s.size());
    switch (__d.size())
    {
    case 1:
        break;
    case 3:
        __d[2] = __d[0];
        break;
    default:
        __d.clear();
        break;
    }
    return __d;
}

// lookup_collatename is very FreeBSD-specific

string __get_collation_name(const char* s);

template <class _CharT>
template <class _ForwardIterator>
typename regex_traits<_CharT>::string_type
regex_traits<_CharT>::__lookup_collatename(_ForwardIterator __f,
                                           _ForwardIterator __l, char) const
{
    string_type __s(__f, __l);
    string_type __r;
    if (!__s.empty())
    {
        __r = __get_collation_name(__s.c_str());
        if (__r.empty() && __s.size() <= 2)
        {
            __r = __col_->transform(__s.data(), __s.data() + __s.size());
            if (__r.size() == 1 || __r.size() == 12)
                __r = __s;
            else
                __r.clear();
        }
    }
    return __r;
}

template <class _CharT>
template <class _ForwardIterator>
typename regex_traits<_CharT>::string_type
regex_traits<_CharT>::__lookup_collatename(_ForwardIterator __f,
                                           _ForwardIterator __l, wchar_t) const
{
    string_type __s(__f, __l);
    string __n;
    __n.reserve(__s.size());
    for (typename string_type::const_iterator __i = __s.begin(), __e = __s.end();
                                                              __i != __e; ++__i)
    {
        if (static_cast<unsigned>(*__i) >= 127)
            return string_type();
        __n.push_back(char(*__i));
    }
    string_type __r;
    if (!__s.empty())
    {
        __n = __get_collation_name(__n.c_str());
        if (!__n.empty())
            __r.assign(__n.begin(), __n.end());
        else if (__s.size() <= 2)
        {
            __r = __col_->transform(__s.data(), __s.data() + __s.size());
            if (__r.size() == 1 || __r.size() == 3)
                __r = __s;
            else
                __r.clear();
        }
    }
    return __r;
}

_LIBCPP_END_NAMESPACE_STD

#endif  // _LIBCPP_REGEX