libcxx/test/std/strings/basic.string/string.capacity/reserve_size.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 // <string>
  10
  11 // void reserve(size_type res_arg); // constexpr since C++20
  12
  13 // This test relies on https://llvm.org/PR45368 (841132e) being fixed, which isn't in
  14 // older Apple dylibs.
  15 // XFAIL: using-built-library-before-llvm-12
  16
  17 #include <string>
  18 #include <stdexcept>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22 #include "min_allocator.h"
  23 #include "asan_testing.h"
  24
  25 template <class S>
  26 TEST_CONSTEXPR_CXX20 void
  27 test(typename S::size_type min_cap, typename S::size_type erased_index, typename S::size_type res_arg) {
  28   S s(min_cap, 'a');
  29   s.erase(erased_index);
  30   assert(s.size() == erased_index);
  31   assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
  32   LIBCPP_ASSERT(is_string_asan_correct(s));
  33
  34 #if TEST_STD_VER > 17
  35   typename S::size_type old_cap = s.capacity();
  36 #endif
  37   S s0 = s;
  38   if (res_arg <= s.max_size()) {
  39     s.reserve(res_arg);
  40     LIBCPP_ASSERT(s.__invariants());
  41     assert(s == s0);
  42     assert(s.capacity() >= res_arg);
  43     assert(s.capacity() >= s.size());
  44     LIBCPP_ASSERT(is_string_asan_correct(s));
  45 #if TEST_STD_VER > 17
  46     assert(s.capacity() >= old_cap); // reserve never shrinks as of P0966 (C++20)
  47 #endif
  48   }
  49 #ifndef TEST_HAS_NO_EXCEPTIONS
  50   else if (!TEST_IS_CONSTANT_EVALUATED) {
  51     try {
  52       s.reserve(res_arg);
  53       LIBCPP_ASSERT(s.__invariants());
  54       assert(false);
  55     } catch (std::length_error&) {
  56       assert(res_arg > s.max_size());
  57     }
  58   }
  59 #endif
  60 }
  61
  62 template <class S>
  63 TEST_CONSTEXPR_CXX20 void test_string() {
  64   {
  65     test<S>(0, 0, 5);
  66     test<S>(0, 0, 10);
  67     test<S>(0, 0, 50);
  68   }
  69   {
  70     test<S>(100, 1, 5);
  71     test<S>(100, 50, 5);
  72     test<S>(100, 50, 10);
  73     test<S>(100, 50, 50);
  74     test<S>(100, 50, 100);
  75     test<S>(100, 50, 1000);
  76     test<S>(100, 50, S::npos);
  77   }
  78 }
  79
  80 TEST_CONSTEXPR_CXX20 bool test() {
  81   test_string<std::string>();
  82 #if TEST_STD_VER >= 11
  83   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
  84 #endif
  85
  86   return true;
  87 }
  88
  89 int main(int, char**) {
  90   test();
  91 #if TEST_STD_VER > 17
  92   static_assert(test());
  93 #endif
  94
  95   return 0;
  96 }