A few bits of N2994 didn't get fully implemented a long time ago. Thanks to STL@microsoft.com for the bug report

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@235134 91177308-0d34-0410-b5e6-96231b3b80d8

include/iterator

@@ -214,7 +214,7 @@ public:
     typedef traits traits_type;
     typedef basic_istream<charT,traits> istream_type;
 
-    istream_iterator();
+    constexpr istream_iterator();
     istream_iterator(istream_type& s);
     istream_iterator(const istream_iterator& x);
     ~istream_iterator();
@@ -765,7 +765,7 @@ private:
     istream_type* __in_stream_;
     _Tp __value_;
 public:
-    _LIBCPP_INLINE_VISIBILITY istream_iterator() : __in_stream_(0) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
     _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(&__s)
         {
             if (!(*__in_stream_ >> __value_))

include/ratio

@@ -21,8 +21,8 @@ template <intmax_t N, intmax_t D = 1>
 class ratio
 {
 public:
-    static const intmax_t num;
-    static const intmax_t den;
+    static constexpr intmax_t num;
+    static constexpr intmax_t den;
     typedef ratio<num, den> type;
 };
 
@@ -236,13 +236,13 @@ class _LIBCPP_TYPE_VIS_ONLY ratio
     static_assert(__static_abs<_Num>::value >= 0, "ratio numerator is out of range");
     static_assert(_Den != 0, "ratio divide by 0");
     static_assert(__static_abs<_Den>::value >  0, "ratio denominator is out of range");
-    static const intmax_t __na = __static_abs<_Num>::value;
-    static const intmax_t __da = __static_abs<_Den>::value;
-    static const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
-    static const intmax_t __gcd = __static_gcd<__na, __da>::value;
+    static _LIBCPP_CONSTEXPR const intmax_t __na = __static_abs<_Num>::value;
+    static _LIBCPP_CONSTEXPR const intmax_t __da = __static_abs<_Den>::value;
+    static _LIBCPP_CONSTEXPR const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
+    static _LIBCPP_CONSTEXPR const intmax_t __gcd = __static_gcd<__na, __da>::value;
 public:
-    static const intmax_t num = __s * __na / __gcd;
-    static const intmax_t den = __da / __gcd;
+    static _LIBCPP_CONSTEXPR const intmax_t num = __s * __na / __gcd;
+    static _LIBCPP_CONSTEXPR const intmax_t den = __da / __gcd;
 
     typedef ratio<num, den> type;
 };

test/std/iterators/stream.iterators/istream.iterator/istream.iterator.cons/default.fail.cpp

@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// class istream_iterator
+
+// constexpr istream_iterator();
+
+#include <iterator>
+#include <cassert>
+
+struct S { S(); }; // not constexpr 
+
+int main()
+{
+#if __cplusplus >= 201103L
+    {
+    constexpr std::istream_iterator<S> it;
+    }
+#else
+#error "C++11 only test"
+#endif
+}

test/std/iterators/stream.iterators/istream.iterator/istream.iterator.cons/default.pass.cpp

@@ -11,13 +11,20 @@
 
 // class istream_iterator
 
-// istream_iterator();
+// constexpr istream_iterator();
 
 #include <iterator>
 #include <cassert>
 
 int main()
 {
-    std::istream_iterator<int> i;
-    assert(i == std::istream_iterator<int>());
+    {
+    typedef std::istream_iterator<int> T;
+    T it;
+    assert(it == T());
+#if __cplusplus >= 201103L
+    constexpr T it2;
+#endif
+    }
+    
 }

test/std/iterators/stream.iterators/istream.iterator/types.pass.cpp

@@ -19,9 +19,14 @@
 //     typedef traits traits_type;
 //     typedef basic_istream<charT,traits> istream_type;
 //     ...
+//
+//   If T is a literal type, then the default constructor shall be a constexpr constructor.
+//   If T is a literal type, then this constructor shall be a trivial copy constructor.
+//   If T is a literal type, then this destructor shall be a trivial destructor.
 
 #include <iterator>
 #include <type_traits>
+#include <string>
 
 int main()
 {
@@ -32,6 +37,9 @@ int main()
     static_assert((std::is_same<I1::char_type, char>::value), "");
     static_assert((std::is_same<I1::traits_type, std::char_traits<char> >::value), "");
     static_assert((std::is_same<I1::istream_type, std::istream>::value), "");
+    static_assert( std::is_trivially_copy_constructible<I1>::value, "");
+    static_assert( std::is_trivially_destructible<I1>::value, "");
+
     typedef std::istream_iterator<unsigned, wchar_t> I2;
     static_assert((std::is_convertible<I2,
         std::iterator<std::input_iterator_tag, unsigned, std::ptrdiff_t,
@@ -39,4 +47,10 @@ int main()
     static_assert((std::is_same<I2::char_type, wchar_t>::value), "");
     static_assert((std::is_same<I2::traits_type, std::char_traits<wchar_t> >::value), "");
     static_assert((std::is_same<I2::istream_type, std::wistream>::value), "");
+    static_assert( std::is_trivially_copy_constructible<I2>::value, "");
+    static_assert( std::is_trivially_destructible<I2>::value, "");
+
+    typedef std::istream_iterator<std::string> I3;
+    static_assert(!std::is_trivially_copy_constructible<I3>::value, "");
+    static_assert(!std::is_trivially_destructible<I3>::value, "");
 }

test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator.cons/default.pass.cpp

@@ -10,8 +10,11 @@
 // <iterator>
 
 // istreambuf_iterator
-
+//
 // istreambuf_iterator() throw();
+//
+// All specializations of istreambuf_iterator shall have a trivial copy constructor, 
+//    a constexpr default constructor and a trivial destructor.
 
 #include <iterator>
 #include <sstream>
@@ -20,11 +23,19 @@
 int main()
 {
     {
-        std::istreambuf_iterator<char> i;
-        assert(i == std::istreambuf_iterator<char>());
+        typedef std::istreambuf_iterator<char> T;
+        T it;
+        assert(it == T());
+#if __cplusplus >= 201103L
+        constexpr T it2;
+#endif
     }
     {
-        std::istreambuf_iterator<wchar_t> i;
-        assert(i == std::istreambuf_iterator<wchar_t>());
+        typedef std::istreambuf_iterator<wchar_t> T;
+        T it;
+        assert(it == T());
+#if __cplusplus >= 201103L
+        constexpr T it2;
+#endif
     }
 }

test/std/iterators/stream.iterators/istreambuf.iterator/types.pass.cpp

@@ -22,6 +22,9 @@
 //     typedef basic_streambuf<charT,traits> streambuf_type;
 //     typedef basic_istream<charT,traits>   istream_type;
 //     ...
+//
+// All specializations of istreambuf_iterator shall have a trivial copy constructor, 
+//    a constexpr default constructor and a trivial destructor.
 
 #include <iterator>
 #include <string>
@@ -38,6 +41,9 @@ int main()
     static_assert((std::is_same<I1::int_type, I1::traits_type::int_type>::value), "");
     static_assert((std::is_same<I1::streambuf_type, std::streambuf>::value), "");
     static_assert((std::is_same<I1::istream_type, std::istream>::value), "");
+    static_assert((std::is_nothrow_default_constructible<I1>::value), "" );
+    static_assert((std::is_trivially_copy_constructible<I1>::value), "" );
+    static_assert((std::is_trivially_destructible<I1>::value), "" );
 
     typedef std::istreambuf_iterator<wchar_t> I2;
     static_assert((std::is_convertible<I2,
@@ -48,4 +54,7 @@ int main()
     static_assert((std::is_same<I2::int_type, I2::traits_type::int_type>::value), "");
     static_assert((std::is_same<I2::streambuf_type, std::wstreambuf>::value), "");
     static_assert((std::is_same<I2::istream_type, std::wistream>::value), "");
+    static_assert((std::is_nothrow_default_constructible<I2>::value), "" );
+    static_assert((std::is_trivially_copy_constructible<I2>::value), "" );
+    static_assert((std::is_trivially_destructible<I2>::value), "" );
 }

test/std/utilities/ratio/ratio.ratio/ratio.pass.cpp

@@ -7,7 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// test ratio:  The static data members num and den shall have thcommon
+// test ratio:  The static data members num and den shall have the common
 //    divisor of the absolute values of N and D:
 
 #include <ratio>