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
This commit is contained in:
Marshall Clow
2017-01-04 17:58:17 +00:00
parent 1fbd97cfd5
commit e22af6b758
6 changed files with 157 additions and 54 deletions

View File

@@ -10,12 +10,25 @@
// XFAIL: c++03, c++98
// <iterator>
// 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 E> reverse_iterator<const E*> rbegin(initializer_list<E> il);
// template <class E> reverse_iterator<const E*> rend(initializer_list<E> il);
// 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 cbegin(const C& c) -> decltype(std::begin(c)); // C++14
// template <class C> constexpr auto cend(const C& c) -> decltype(std::end(c)); // C++14
// 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 E> constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il);
// template <class E> constexpr reverse_iterator<const E*> rend (initializer_list<E> il);
//
// 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 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
//
// All of these are constexpr in C++17
#include "test_macros.h"
@@ -26,6 +39,10 @@
#include <list>
#include <initializer_list>
// std::array is explicitly allowed to be initialized with A a = { init-list };.
// Disable the missing braces warning for this reason.
#include "disable_missing_braces_warning.h"
template<typename C>
void test_const_container( const C & c, typename C::value_type val ) {
assert ( std::begin(c) == c.begin());
@@ -142,4 +159,43 @@ int main(){
constexpr const int *e = std::cend(arrA);
static_assert(e - b == 3, "");
#endif
#if TEST_STD_VER > 14
{
typedef std::array<int, 5> C;
constexpr const C c{0,1,2,3,4};
static_assert ( c.begin() == std::begin(c), "");
static_assert ( c.cbegin() == std::cbegin(c), "");
static_assert ( c.end() == std::end(c), "");
static_assert ( c.cend() == std::cend(c), "");
static_assert ( c.rbegin() == std::rbegin(c), "");
static_assert ( c.crbegin() == std::crbegin(c), "");
static_assert ( c.rend() == std::rend(c), "");
static_assert ( c.crend() == std::crend(c), "");
static_assert ( std::begin(c) != std::end(c), "");
static_assert ( std::rbegin(c) != std::rend(c), "");
static_assert ( std::cbegin(c) != std::cend(c), "");
static_assert ( std::crbegin(c) != std::crend(c), "");
static_assert ( *c.begin() == 0, "");
static_assert ( *c.rbegin() == 4, "");
static_assert ( *std::begin(c) == 0, "" );
static_assert ( *std::cbegin(c) == 0, "" );
static_assert ( *std::rbegin(c) == 4, "" );
static_assert ( *std::crbegin(c) == 4, "" );
}
{
static constexpr const int c[] = {0,1,2,3,4};
static_assert ( *std::begin(c) == 0, "" );
static_assert ( *std::cbegin(c) == 0, "" );
static_assert ( *std::rbegin(c) == 4, "" );
static_assert ( *std::crbegin(c) == 4, "" );
}
#endif
}