libcxx/test/std/strings/strings.erasure/erase.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
  10
  11 // <string>
  12
  13 // template <class charT, class traits, class Allocator, class U>
  14 //   typename basic_string<charT, traits, Allocator>::size_type
  15 //   erase(basic_string<charT, traits, Allocator>& c, const U& value);
  16
  17 #include <string>
  18 #include <optional>
  19
  20 #include "test_macros.h"
  21 #include "test_allocator.h"
  22 #include "min_allocator.h"
  23
  24 template <class S, class U>
  25 void test0(S s, U val, S expected, std::size_t expected_erased_count) {
  26   ASSERT_SAME_TYPE(typename S::size_type, decltype(std::erase(s, val)));
  27   assert(expected_erased_count == std::erase(s, val));
  28   LIBCPP_ASSERT(s.__invariants());
  29   assert(s == expected);
  30 }
  31
  32 template <class S>
  33 void test() {
  34   test0(S(""), 'a', S(""), 0);
  35
  36   test0(S("a"), 'a', S(""), 1);
  37   test0(S("a"), 'b', S("a"), 0);
  38
  39   test0(S("ab"), 'a', S("b"), 1);
  40   test0(S("ab"), 'b', S("a"), 1);
  41   test0(S("ab"), 'c', S("ab"), 0);
  42   test0(S("aa"), 'a', S(""), 2);
  43   test0(S("aa"), 'c', S("aa"), 0);
  44
  45   test0(S("abc"), 'a', S("bc"), 1);
  46   test0(S("abc"), 'b', S("ac"), 1);
  47   test0(S("abc"), 'c', S("ab"), 1);
  48   test0(S("abc"), 'd', S("abc"), 0);
  49
  50   test0(S("aab"), 'a', S("b"), 2);
  51   test0(S("aab"), 'b', S("aa"), 1);
  52   test0(S("aab"), 'c', S("aab"), 0);
  53   test0(S("abb"), 'a', S("bb"), 1);
  54   test0(S("abb"), 'b', S("a"), 2);
  55   test0(S("abb"), 'c', S("abb"), 0);
  56   test0(S("aaa"), 'a', S(""), 3);
  57   test0(S("aaa"), 'b', S("aaa"), 0);
  58
  59   //  Test cross-type erasure
  60   using opt = std::optional<typename S::value_type>;
  61   test0(S("aba"), opt(), S("aba"), 0);
  62   test0(S("aba"), opt('a'), S("b"), 2);
  63   test0(S("aba"), opt('b'), S("aa"), 1);
  64   test0(S("aba"), opt('c'), S("aba"), 0);
  65 }
  66
  67 int main(int, char**) {
  68   test<std::string>();
  69   test<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
  70   test<std::basic_string<char, std::char_traits<char>, test_allocator<char>>>();
  71
  72   return 0;
  73 }