libcxx/test/std/strings/basic.string/string.cons/brace_assignment.pass.cpp

   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
   9 // UNSUPPORTED: c++03
  10
  11 // <string>
  12
  13 // basic_string<charT,traits,Allocator>&
  14 //   operator=(basic_string<charT,traits,Allocator>&& str); // constexpr since C++20
  15
  16 #include <string>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20
  21 TEST_CONSTEXPR_CXX20 bool test() {
  22   // Test that assignment from {} and {ptr, len} are allowed and are not
  23   // ambiguous.
  24   {
  25     std::string s = "hello world";
  26     s             = {};
  27     assert(s.empty());
  28   }
  29   {
  30     std::string s = "hello world";
  31     s             = {"abc", 2};
  32     assert(s == "ab");
  33   }
  34
  35   return true;
  36 }
  37
  38 int main(int, char**) {
  39   test();
  40 #if TEST_STD_VER > 17
  41   static_assert(test());
  42 #endif
  43
  44   return 0;
  45 }