1 //===---------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===---------------------------------------------------------------------===// 8 // UNSUPPORTED: c++03, c++11, c++14, c++17 9 10 // <span> 11 12 // template <class It> 13 // constexpr explicit(Extent != dynamic_extent) span(It first, size_type count); 14 // If Extent is not equal to dynamic_extent, then count shall be equal to Extent. 15 // 16 17 #include <cassert> 18 #include <cstddef> 19 #include <iterator> 20 #include <span> 21 #include <type_traits> 22 23 template <std::size_t Extent> 24 constexpr void test_constructibility() { 25 struct Other {}; 26 static_assert(std::is_constructible_v<std::span<int, Extent>, int*, std::size_t>); 27 static_assert(!std::is_constructible_v<std::span<int, Extent>, const int*, std::size_t>); 28 static_assert(std::is_constructible_v<std::span<const int, Extent>, int*, std::size_t>); 29 static_assert(std::is_constructible_v<std::span<const int, Extent>, const int*, std::size_t>); 30 static_assert(!std::is_constructible_v<std::span<int, Extent>, volatile int*, std::size_t>); 31 static_assert(!std::is_constructible_v<std::span<int, Extent>, const volatile int*, std::size_t>); 32 static_assert(!std::is_constructible_v<std::span<const int, Extent>, volatile int*, std::size_t>); 33 static_assert(!std::is_constructible_v<std::span<const int, Extent>, const volatile int*, std::size_t>); 34 static_assert(!std::is_constructible_v<std::span<volatile int, Extent>, const int*, std::size_t>); 35 static_assert(!std::is_constructible_v<std::span<volatile int, Extent>, const volatile int*, std::size_t>); 36 static_assert( 37 !std::is_constructible_v<std::span<int, Extent>, double*, std::size_t>); // iterator type differs from span type 38 static_assert(!std::is_constructible_v<std::span<int, Extent>, std::size_t, size_t>); 39 static_assert(!std::is_constructible_v<std::span<int, Extent>, Other*, std::size_t>); // unrelated iterator type 40 } 41 42 template <class T> 43 constexpr bool test_ctor() { 44 T val[2] = {}; 45 auto s1 = std::span<T>(val, 2); 46 auto s2 = std::span<T, 2>(val, 2); 47 assert(s1.data() == std::data(val) && s1.size() == std::size(val)); 48 assert(s2.data() == std::data(val) && s2.size() == std::size(val)); 49 return true; 50 } 51 52 constexpr bool test() { 53 test_constructibility<std::dynamic_extent>(); 54 test_constructibility<3>(); 55 56 struct A {}; 57 test_ctor<int>(); 58 test_ctor<A>(); 59 60 return true; 61 } 62 63 int main(int, char**) { 64 test(); 65 static_assert(test()); 66 67 return 0; 68 } 69