libcxx/test/std/strings/basic.string/string.ops/string_substr/substr_rvalue.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, c++11, c++14, c++17, c++20
  10
  11 // <string>
  12
  13 // constexpr basic_string substr(size_type pos = 0, size_type n = npos) &&;
  14
  15 #include <algorithm>
  16 #include <stdexcept>
  17 #include <string>
  18
  19 #include "constexpr_char_traits.h"
  20 #include "make_string.h"
  21 #include "min_allocator.h"
  22 #include "test_allocator.h"
  23
  24 #define STR(string) MAKE_CSTRING(typename S::value_type, string)
  25
  26 constexpr struct should_throw_exception_t {
  27 } should_throw_exception;
  28
  29 template <class S>
  30 constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, const S expected) {
  31   S str = std::move(orig).substr(pos, n);
  32   LIBCPP_ASSERT(orig.__invariants());
  33   LIBCPP_ASSERT(str.__invariants());
  34   assert(str == expected);
  35 }
  36
  37 template <class S>
  38 constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, should_throw_exception_t) {
  39 #ifndef TEST_HAS_NO_EXCEPTIONS
  40   if (!std::is_constant_evaluated()) {
  41     try {
  42       S str = std::move(orig).substr(pos, n);
  43       assert(false);
  44     } catch (const std::out_of_range&) {
  45     }
  46   }
  47 #else
  48   (void)orig;
  49   (void)pos;
  50   (void)n;
  51 #endif
  52 }
  53
  54 template <class S>
  55 constexpr void test_string() {
  56   test<S>(STR(""), 0, 0, STR(""));
  57   test<S>(STR(""), 0, 1, STR(""));
  58   test<S>(STR(""), 1, 0, should_throw_exception);
  59   test<S>(STR(""), 1, 1, should_throw_exception);
  60   test<S>(STR("short string"), 0, 1, STR("s"));
  61   test<S>(STR("short string"), 5, 5, STR(" stri"));
  62   test<S>(STR("short string"), 12, 5, STR(""));
  63   test<S>(STR("short string"), 13, 5, should_throw_exception);
  64   test<S>(STR("long long string so no SSO"), 0, 0, STR(""));
  65   test<S>(STR("long long string so no SSO"), 0, 10, STR("long long "));
  66   test<S>(STR("long long string so no SSO"), 10, 10, STR("string so "));
  67   test<S>(STR("long long string so no SSO"), 20, 10, STR("no SSO"));
  68   test<S>(STR("long long string so no SSO"), 26, 10, STR(""));
  69   test<S>(STR("long long string so no SSO"), 27, 0, should_throw_exception);
  70 }
  71
  72 template <class CharT, class CharTraits>
  73 constexpr void test_allocators() {
  74   test_string<std::basic_string<CharT, CharTraits, std::allocator<CharT>>>();
  75   test_string<std::basic_string<CharT, CharTraits, min_allocator<CharT>>>();
  76   test_string<std::basic_string<CharT, CharTraits, test_allocator<CharT>>>();
  77 }
  78
  79 template <class CharT>
  80 constexpr void test_char_traits() {
  81   test_allocators<CharT, std::char_traits<CharT>>();
  82   test_allocators<CharT, constexpr_char_traits<CharT>>();
  83 }
  84
  85 constexpr bool test() {
  86   test_char_traits<char>();
  87   test_char_traits<char16_t>();
  88   test_char_traits<char32_t>();
  89 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  90   test_char_traits<wchar_t>();
  91 #endif
  92 #ifndef TEST_HAS_NO_CHAR8_T
  93   test_char_traits<char8_t>();
  94 #endif
  95
  96   return true;
  97 }
  98
  99 int main(int, char**) {
 100   test();
 101   static_assert(test());
 102
 103   return 0;
 104 }