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 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <optional> 12 13 // template <class T, class U, class... Args> 14 // constexpr optional<T> make_optional(initializer_list<U> il, Args&&... args); 15 16 #include <optional> 17 #include <string> 18 #include <memory> 19 #include <cassert> 20 21 #include "test_macros.h" 22 23 struct TestT { 24 int x; 25 int size; 26 constexpr TestT(std::initializer_list<int> il) : x(*il.begin()), size(static_cast<int>(il.size())) {} 27 constexpr TestT(std::initializer_list<int> il, const int*) 28 : x(*il.begin()), size(static_cast<int>(il.size())) {} 29 }; 30 31 int main() 32 { 33 using std::make_optional; 34 { 35 constexpr auto opt = make_optional<TestT>({42, 2, 3}); 36 ASSERT_SAME_TYPE(decltype(opt), const std::optional<TestT>); 37 static_assert(opt->x == 42, ""); 38 static_assert(opt->size == 3, ""); 39 } 40 { 41 constexpr auto opt = make_optional<TestT>({42, 2, 3}, nullptr); 42 static_assert(opt->x == 42, ""); 43 static_assert(opt->size == 3, ""); 44 } 45 { 46 auto opt = make_optional<std::string>({'1', '2', '3'}); 47 assert(*opt == "123"); 48 } 49 { 50 auto opt = make_optional<std::string>({'a', 'b', 'c'}, std::allocator<char>{}); 51 assert(*opt == "abc"); 52 } 53 } 54
