text: // Copyright 2021 The Tint 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
  //
  //     http://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.
  
  #ifndef SRC_UTILS_DEFER_H_
  #define SRC_UTILS_DEFER_H_
  
  #include <utility>
  
  #include "src/utils/concat.h"
  
  namespace tint {
  namespace utils {
  
  /// Defer executes a function or function like object when it is destructed.
  template <typename F>
  class Defer {
   public:
    /// Constructor
    /// @param f the function to call when the Defer is destructed
    explicit Defer(F&& f) : f_(std::move(f)) {}
  
    /// Move constructor
    Defer(Defer&&) = default;
  
    /// Destructor
    /// Calls the deferred function
    ~Defer() { f_(); }
  
   private:
    Defer(const Defer&) = delete;
    Defer& operator=(const Defer&) = delete;
  
    F f_;
  };
  
  /// Constructor
  /// @param f the function to call when the Defer is destructed
  template <typename F>
  inline Defer<F> MakeDefer(F&& f) {
    return Defer<F>(std::forward<F>(f));
  }
  
  }  // namespace utils
  }  // namespace tint
  
  /// TINT_DEFER(S) executes the statement(s) `S` when exiting the current lexical
  /// scope.
  #define TINT_DEFER(S)                          \
    auto TINT_CONCAT(tint_defer_, __COUNTER__) = \
        ::tint::utils::MakeDefer([&] { S; })
  
  #endif  //  SRC_UTILS_DEFER_H_
  