1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <array> 11 // UNSUPPORTED: c++98, c++03, c++11, c++14 12 // UNSUPPORTED: clang-5, apple-clang-9 13 // UNSUPPORTED: libcpp-no-deduction-guides 14 // Clang 5 will generate bad implicit deduction guides 15 // Specifically, for the copy constructor. 16 17 18 // template <class T, class... U> 19 // array(T, U...) -> array<T, 1 + sizeof...(U)>; 20 // 21 // Requires: (is_same_v<T, U> && ...) is true. Otherwise the program is ill-formed. 22 23 24 #include <array> 25 #include <cassert> 26 #include <cstddef> 27 28 // std::array is explicitly allowed to be initialized with A a = { init-list };. 29 // Disable the missing braces warning for this reason. 30 #include "disable_missing_braces_warning.h" 31 32 #include "test_macros.h" 33 34 int main() 35 { 36 // Test the explicit deduction guides 37 { 38 std::array arr{1,2,3}; // array(T, U...) 39 static_assert(std::is_same_v<decltype(arr), std::array<int, 3>>, ""); 40 assert(arr[0] == 1); 41 assert(arr[1] == 2); 42 assert(arr[2] == 3); 43 } 44 45 { 46 const long l1 = 42; 47 std::array arr{1L, 4L, 9L, l1}; // array(T, U...) 48 static_assert(std::is_same_v<decltype(arr)::value_type, long>, ""); 49 static_assert(arr.size() == 4, ""); 50 assert(arr[0] == 1); 51 assert(arr[1] == 4); 52 assert(arr[2] == 9); 53 assert(arr[3] == l1); 54 } 55 56 // Test the implicit deduction guides 57 { 58 std::array<double, 2> source = {4.0, 5.0}; 59 std::array arr(source); // array(array) 60 static_assert(std::is_same_v<decltype(arr), decltype(source)>, ""); 61 static_assert(std::is_same_v<decltype(arr), std::array<double, 2>>, ""); 62 assert(arr[0] == 4.0); 63 assert(arr[1] == 5.0); 64 } 65 } 66
