Implement the last bit of P0031: 'A Proposal to Add Constexpr Modifiers to reverse_iterator, move_iterator, array and Range Access' for C++17

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290976 91177308-0d34-0410-b5e6-96231b3b80d8

include/array

diff --git a/include/array b/include/array
index d3f8463..7e205cb 100644
--- a/include/array
+++ b/include/array
@@ -149,31 +149,31 @@
         { _VSTD::swap_ranges(__elems_, __elems_ + _Size, __a.__elems_);}
 
     // iterators:
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     iterator begin() _NOEXCEPT {return iterator(__elems_);}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_iterator begin() const _NOEXCEPT {return const_iterator(__elems_);}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     iterator end() _NOEXCEPT {return iterator(__elems_ + _Size);}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_iterator end() const _NOEXCEPT {return const_iterator(__elems_ + _Size);}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
     // capacity:
@@ -195,9 +195,9 @@
     _LIBCPP_INLINE_VISIBILITY reference back()              {return __elems_[_Size > 0 ? _Size-1 : 0];}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  {return __elems_[_Size > 0 ? _Size-1 : 0];}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     value_type* data() _NOEXCEPT {return __elems_;}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const value_type* data() const _NOEXCEPT {return __elems_;}
 };
 

include/iterator

diff --git a/include/iterator b/include/iterator
index ba9a83b..797ec53 100644
--- a/include/iterator
+++ b/include/iterator
@@ -378,25 +378,25 @@
     bool failed() const noexcept;
 };
 
-template <class C> auto begin(C& c) -> decltype(c.begin());
-template <class C> auto begin(const C& c) -> decltype(c.begin());
-template <class C> auto end(C& c) -> decltype(c.end());
-template <class C> auto end(const C& c) -> decltype(c.end());
-template <class T, size_t N> T* begin(T (&array)[N]);
-template <class T, size_t N> T* end(T (&array)[N]);
+template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
+template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
+template <class C> constexpr auto end(C& c) -> decltype(c.end());
+template <class C> constexpr auto end(const C& c) -> decltype(c.end());
+template <class T, size_t N> constexpr T* begin(T (&array)[N]);
+template <class T, size_t N> constexpr T* end(T (&array)[N]);
 
-template <class C> auto cbegin(const C& c) -> decltype(std::begin(c));        // C++14
-template <class C> auto cend(const C& c) -> decltype(std::end(c));            // C++14
-template <class C> auto rbegin(C& c) -> decltype(c.rbegin());                 // C++14
-template <class C> auto rbegin(const C& c) -> decltype(c.rbegin());           // C++14
-template <class C> auto rend(C& c) -> decltype(c.rend());                     // C++14
-template <class C> auto rend(const C& c) -> decltype(c.rend());               // C++14
-template <class E> reverse_iterator<const E*> rbegin(initializer_list<E> il); // C++14
-template <class E> reverse_iterator<const E*> rend(initializer_list<E> il);   // C++14
-template <class T, size_t N> reverse_iterator<T*> rbegin(T (&array)[N]);      // C++14
-template <class T, size_t N> reverse_iterator<T*> rend(T (&array)[N]);        // C++14
-template <class C> auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
-template <class C> auto crend(const C& c) -> decltype(std::rend(c));          // C++14
+template <class C> auto constexpr cbegin(const C& c) -> decltype(std::begin(c));        // C++14
+template <class C> auto constexpr cend(const C& c) -> decltype(std::end(c));            // C++14
+template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
+template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
+template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
+template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
+template <class E> reverse_iterator<const E*> constexpr rbegin(initializer_list<E> il); // C++14
+template <class E> reverse_iterator<const E*> constexpr rend(initializer_list<E> il);   // C++14
+template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
+template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
+template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
+template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
 
 // 24.8, container access:
 template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
@@ -1616,7 +1616,7 @@
 #if !defined(_LIBCPP_CXX03_LANG)
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto
 begin(_Cp& __c) -> decltype(__c.begin())
 {
@@ -1624,7 +1624,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto
 begin(const _Cp& __c) -> decltype(__c.begin())
 {
@@ -1632,7 +1632,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto
 end(_Cp& __c) -> decltype(__c.end())
 {
@@ -1640,7 +1640,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto
 end(const _Cp& __c) -> decltype(__c.end())
 {
@@ -1650,28 +1650,28 @@
 #if _LIBCPP_STD_VER > 11
 
 template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
 {
     return reverse_iterator<_Tp*>(__array + _Np);
 }
 
 template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
 {
     return reverse_iterator<_Tp*>(__array);
 }
 
 template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
 {
     return reverse_iterator<const _Ep*>(__il.end());
 }
 
 template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
 {
     return reverse_iterator<const _Ep*>(__il.begin());
@@ -1692,42 +1692,42 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
 {
     return __c.rbegin();
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
 {
     return __c.rbegin();
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto rend(_Cp& __c) -> decltype(__c.rend())
 {
     return __c.rend();
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto rend(const _Cp& __c) -> decltype(__c.rend())
 {
     return __c.rend();
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
 {
     return _VSTD::rbegin(__c);
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
 {
     return _VSTD::rend(__c);