test/std/utilities/format/format.formatter/format.parse.ctx/advance_to.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
// UNSUPPORTED: libcpp-no-concepts

// <format>

// constexpr void advance_to(const_iterator it);

#include <format>
#include <cassert>

#include "test_macros.h"

template <class CharT>
constexpr void test(const CharT* fmt) {
  {
    std::basic_format_parse_context<CharT> context(fmt);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == &fmt[1]);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == &fmt[2]);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == context.end());
  }
  {
    std::basic_string_view view{fmt};
    std::basic_format_parse_context context(view);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == view.begin() + 1);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == view.begin() + 2);

    context.advance_to(context.begin() + 1);
    assert(context.begin() == context.end());
  }
}

constexpr bool test() {
  test("abc");
  test(L"abc");
#ifndef _LIBCPP_NO_HAS_CHAR8_T
  test(u8"abc");
#endif
#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
  test(u"abc");
  test(U"abc");
#endif

  return true;
}

int main(int, char**) {
  test();
  static_assert(test());

  return 0;
}