test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/find.pass.cpp

//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17

// <string>

// template<> struct char_traits<char8_t>

// static constexpr const char_type* find(const char_type* s, size_t n, const char_type& a);

#include <string>
#include <cassert>

#include "test_macros.h"

#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
constexpr bool test_constexpr()
{
    constexpr const char8_t *p = u8"123";
    return std::char_traits<char8_t>::find(p, 3, u8'1') == p
        && std::char_traits<char8_t>::find(p, 3, u8'2') == p + 1
        && std::char_traits<char8_t>::find(p, 3, u8'3') == p + 2
        && std::char_traits<char8_t>::find(p, 3, u8'4') == nullptr;
}

int main(int, char**)
{
    char8_t s1[] = {1, 2, 3};
    assert(std::char_traits<char8_t>::find(s1, 3, char8_t(1)) == s1);
    assert(std::char_traits<char8_t>::find(s1, 3, char8_t(2)) == s1+1);
    assert(std::char_traits<char8_t>::find(s1, 3, char8_t(3)) == s1+2);
    assert(std::char_traits<char8_t>::find(s1, 3, char8_t(4)) == 0);
    assert(std::char_traits<char8_t>::find(s1, 3, char8_t(0)) == 0);
    assert(std::char_traits<char8_t>::find(NULL, 0, char8_t(0)) == 0);

    static_assert(test_constexpr(), "" );
    return 0;
}
#else
int main(int, char**) {
  return 0;
}
#endif