defer.h 1.5 KB

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  1. #pragma once
  2. /*
  3. * Copyright 2018-present Facebook, Inc.
  4. *
  5. * Licensed under the Apache License, Version 2.0 (the "License");
  6. * you may not use this file except in compliance with the License.
  7. * You may obtain a copy of the License at
  8. *
  9. * http://www.apache.org/licenses/LICENSE-2.0
  10. *
  11. * Unless required by applicable law or agreed to in writing, software
  12. * distributed under the License is distributed on an "AS IS" BASIS,
  13. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14. * See the License for the specific language governing permissions and
  15. * limitations under the License.
  16. */
  17. #include <folly/experimental/pushmi/o/extension_operators.h>
  18. #include <folly/experimental/pushmi/o/submit.h>
  19. #include <folly/experimental/pushmi/receiver.h>
  20. #include <folly/experimental/pushmi/single_sender.h>
  21. namespace pushmi {
  22. namespace operators {
  23. PUSHMI_INLINE_VAR constexpr struct defer_fn {
  24. private:
  25. template <class F>
  26. struct impl {
  27. F f_;
  28. PUSHMI_TEMPLATE(class Data, class Out)
  29. (requires Receiver<Out>)
  30. void operator()(Data&, Out out) {
  31. auto sender = f_();
  32. ::pushmi::submit(sender, std::move(out));
  33. }
  34. };
  35. public:
  36. PUSHMI_TEMPLATE(class F)
  37. (requires Invocable<F&>)
  38. auto operator()(F f) const {
  39. struct sender_base : single_sender<> {
  40. using properties = properties_t<invoke_result_t<F&>>;
  41. };
  42. return make_single_sender(sender_base{}, impl<F>{std::move(f)});
  43. }
  44. } defer{};
  45. } // namespace operators
  46. } // namespace pushmi