include/unifex/defer.hpp

/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * Licensed under the Apache License Version 2.0 with LLVM Exceptions
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *   https://llvm.org/LICENSE.txt
 *
 * 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.
 */
#pragma once

#include <unifex/config.hpp>
#include <unifex/just.hpp>
#include <unifex/let_value.hpp>

#include <unifex/detail/prologue.hpp>

namespace unifex
{
  namespace _defer {
    inline const struct _fn {
      template (typename Callable)
        (requires callable<Callable> AND sender<callable_result_t<Callable>>)
      constexpr auto operator()(Callable&& callable) const {
        return let_value(just(), (Callable&&) callable);
      }
    } defer{};
  } // namespace _defer
  using _defer::defer;
} // namespace unifex

#include <unifex/detail/epilogue.hpp>