70 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===----------------------------------------------------------------------===//
 | |
| //
 | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 | |
| // See https://llvm.org/LICENSE.txt for license information.
 | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| 
 | |
| // <string>
 | |
| 
 | |
| // const_reference operator[](size_type pos) const; // constexpr since C++20
 | |
| //       reference operator[](size_type pos); // constexpr since C++20
 | |
| 
 | |
| #include <string>
 | |
| #include <cassert>
 | |
| 
 | |
| #include "test_macros.h"
 | |
| #include "min_allocator.h"
 | |
| 
 | |
| TEST_CONSTEXPR_CXX20 bool test() {
 | |
|   {
 | |
|     typedef std::string S;
 | |
|     S s("0123456789");
 | |
|     const S& cs = s;
 | |
|     ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
 | |
|     ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
 | |
|     LIBCPP_ASSERT_NOEXCEPT(    s[0]);
 | |
|     LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
 | |
|     for (S::size_type i = 0; i < cs.size(); ++i)
 | |
|     {
 | |
|         assert(s[i] == static_cast<char>('0' + i));
 | |
|         assert(cs[i] == s[i]);
 | |
|     }
 | |
|     assert(cs[cs.size()] == '\0');
 | |
|     const S s2 = S();
 | |
|     assert(s2[0] == '\0');
 | |
|   }
 | |
| #if TEST_STD_VER >= 11
 | |
|   {
 | |
|     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
 | |
|     S s("0123456789");
 | |
|     const S& cs = s;
 | |
|     ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
 | |
|     ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
 | |
|     LIBCPP_ASSERT_NOEXCEPT(    s[0]);
 | |
|     LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
 | |
|     for (S::size_type i = 0; i < cs.size(); ++i)
 | |
|     {
 | |
|         assert(s[i] == static_cast<char>('0' + i));
 | |
|         assert(cs[i] == s[i]);
 | |
|     }
 | |
|     assert(cs[cs.size()] == '\0');
 | |
|     const S s2 = S();
 | |
|     assert(s2[0] == '\0');
 | |
|   }
 | |
| #endif
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| int main(int, char**)
 | |
| {
 | |
|   test();
 | |
| #if TEST_STD_VER > 17
 | |
|   static_assert(test());
 | |
| #endif
 | |
| 
 | |
|   return 0;
 | |
| }
 |