libcxx/test/std/strings/basic.string/string.starts_with/starts_with.ptr.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>

// constexpr bool starts_with(const CharT *x) const;

#include <string>
#include <cassert>

#include "test_macros.h"

template <class S>
constexpr void test_string() {
  const char* s = "abcde";
  S s0{};
  S s1{s, 1};
  S s2{s, 2};
  //     S  s3 { s, 3 };
  //     S  s4 { s, 4 };
  //     S  s5 { s, 5 };
  S sNot{"def", 3};

  LIBCPP_ASSERT_NOEXCEPT(s0.starts_with(""));

  assert(s0.starts_with(""));
  assert(!s0.starts_with("a"));

  assert(s1.starts_with(""));
  assert(s1.starts_with("a"));
  assert(!s1.starts_with("ab"));
  assert(!s1.starts_with("abc"));
  assert(!s1.starts_with("abcd"));
  assert(!s1.starts_with("abcde"));
  assert(!s1.starts_with("def"));

  assert(s2.starts_with(""));
  assert(s2.starts_with("a"));
  assert(s2.starts_with("ab"));
  assert(!s2.starts_with("abc"));
  assert(!s2.starts_with("abcd"));
  assert(!s2.starts_with("abcde"));
  assert(!s2.starts_with("def"));

  assert(sNot.starts_with(""));
  assert(!sNot.starts_with("a"));
  assert(!sNot.starts_with("ab"));
  assert(!sNot.starts_with("abc"));
  assert(!sNot.starts_with("abcd"));
  assert(!sNot.starts_with("abcde"));
  assert(sNot.starts_with("def"));
}

constexpr bool test() {
  test_string<std::string>();

  return true;
}

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

  return 0;
}