// Copyright 2017 The Abseil Authors.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

// -----------------------------------------------------------------------------

// File: string_view.h

// -----------------------------------------------------------------------------

//

// Historical note: Abseil once provided an implementation of

// `absl::string_view` as a polyfill for `std::string_view` prior to C++17. Now

// that C++17 is required, `absl::string_view` is an alias for

// `std::string_view`

#ifndef ABSL_STRINGS_STRING_VIEW_H_

#define ABSL_STRINGS_STRING_VIEW_H_

#include <algorithm>

#include <string_view>

#include "absl/base/attributes.h"

#include "absl/base/config.h"

#include "absl/base/nullability.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

using std::string_view;

// ClippedSubstr()

//

// Like `s.substr(pos, n)`, but clips `pos` to an upper bound of `s.size()`.

// Provided because std::string_view::substr throws if `pos > size()`

inline string_view ClippedSubstr(string_view s ABSL_ATTRIBUTE_LIFETIME_BOUND,

                                 size_t pos, size_t n = string_view::npos) {

  pos = (std::min)(pos, static_cast<size_t>(s.size()));

  return s.substr(pos, n);

}

// NullSafeStringView()

//

// Creates an `absl::string_view` from a pointer `p` even if it's null-valued.

// This function should be used where an `absl::string_view` can be created from

// a possibly-null pointer.

constexpr string_view NullSafeStringView(const char* absl_nullable p) {

  return p ? string_view(p) : string_view();

}

ABSL_NAMESPACE_END

}  // namespace absl

#endif  // ABSL_STRINGS_STRING_VIEW_H_