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 #include "asan_testing.h"
  24
  25 #define STR(string) MAKE_CSTRING(typename S::value_type, string)
  26
  27 constexpr struct should_throw_exception_t {
  28 } should_throw_exception;
  29
  30 template <class S>
  31 constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, const S expected) {
  32   S str = std::move(orig).substr(pos, n);
  33   LIBCPP_ASSERT(orig.__invariants());
  34   LIBCPP_ASSERT(str.__invariants());
  35   assert(str == expected);
  36   LIBCPP_ASSERT(is_string_asan_correct(orig));
  37   LIBCPP_ASSERT(is_string_asan_correct(str));
  38 }
  39
  40 template <class S>
  41 constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, should_throw_exception_t) {
  42 #ifndef TEST_HAS_NO_EXCEPTIONS
  43   if (!std::is_constant_evaluated()) {
  44     try {
  45       S str = std::move(orig).substr(pos, n);
  46       assert(false);
  47     } catch (const std::out_of_range&) {
  48     }
  49   }
  50 #else
  51   (void)orig;
  52   (void)pos;
  53   (void)n;
  54 #endif
  55 }
  56
  57 template <class S>
  58 constexpr void test_string() {
  59   test<S>(STR(""), 0, 0, STR(""));
  60   test<S>(STR(""), 0, 1, STR(""));
  61   test<S>(STR(""), 1, 0, should_throw_exception);
  62   test<S>(STR(""), 1, 1, should_throw_exception);
  63   test<S>(STR("short string"), 0, 1, STR("s"));
  64   test<S>(STR("short string"), 5, 5, STR(" stri"));
  65   test<S>(STR("short string"), 12, 5, STR(""));
  66   test<S>(STR("short string"), 13, 5, should_throw_exception);
  67   test<S>(STR("long long string so no SSO"), 0, 0, STR(""));
  68   test<S>(STR("long long string so no SSO"), 0, 10, STR("long long "));
  69   test<S>(STR("long long string so no SSO"), 10, 10, STR("string so "));
  70   test<S>(STR("long long string so no SSO"), 20, 10, STR("no SSO"));
  71   test<S>(STR("long long string so no SSO"), 26, 10, STR(""));
  72   test<S>(STR("long long string so no SSO"), 27, 0, should_throw_exception);
  73 }
  74
  75 template <class CharT, class CharTraits>
  76 constexpr void test_allocators() {
  77   test_string<std::basic_string<CharT, CharTraits, std::allocator<CharT>>>();
  78   test_string<std::basic_string<CharT, CharTraits, min_allocator<CharT>>>();
  79   test_string<std::basic_string<CharT, CharTraits, test_allocator<CharT>>>();
  80 }
  81
  82 template <class CharT>
  83 constexpr void test_char_traits() {
  84   test_allocators<CharT, std::char_traits<CharT>>();
  85   test_allocators<CharT, constexpr_char_traits<CharT>>();
  86 }
  87
  88 constexpr bool test() {
  89   test_char_traits<char>();
  90   test_char_traits<char16_t>();
  91   test_char_traits<char32_t>();
  92 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  93   test_char_traits<wchar_t>();
  94 #endif
  95 #ifndef TEST_HAS_NO_CHAR8_T
  96   test_char_traits<char8_t>();
  97 #endif
  98
  99   return true;
 100 }
 101
 102 int main(int, char**) {
 103   test();
 104   static_assert(test());
 105
 106   return 0;
 107 }