mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-23 05:13:04 +03:00
63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
/*!
|
|
@file
|
|
Forward declares `boost::hana::extend`.
|
|
|
|
@copyright Louis Dionne 2013-2016
|
|
Distributed under the Boost Software License, Version 1.0.
|
|
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
|
|
*/
|
|
|
|
#ifndef BOOST_HANA_FWD_EXTEND_HPP
|
|
#define BOOST_HANA_FWD_EXTEND_HPP
|
|
|
|
#include <boost/hana/config.hpp>
|
|
#include <boost/hana/core/when.hpp>
|
|
|
|
|
|
BOOST_HANA_NAMESPACE_BEGIN
|
|
//! Comonadic application of a function to a comonadic value.
|
|
//! @ingroup group-Comonad
|
|
//!
|
|
//! Given a comonadic value and a function accepting a comonadic input,
|
|
//! `extend` returns the result of applying the function to that input
|
|
//! inside the comonadic context.
|
|
//!
|
|
//!
|
|
//! Signature
|
|
//! ---------
|
|
//! Given a Comonad `W` and a function of type \f$ W(T) \to U \f$, the
|
|
//! signature is
|
|
//! \f$
|
|
//! \mathtt{extend} : W(T) \times (W(T) \to U) \to W(U)
|
|
//! \f$
|
|
//!
|
|
//! @param w
|
|
//! A comonadic value to call the function with.
|
|
//!
|
|
//! @param f
|
|
//! A function of signature \f$ W(T) \to U \f$ to be applied to its
|
|
//! comonadic argument inside the comonadic context.
|
|
//!
|
|
//!
|
|
//! Example
|
|
//! -------
|
|
//! @include example/extend.cpp
|
|
#ifdef BOOST_HANA_DOXYGEN_INVOKED
|
|
constexpr auto extend = [](auto&& w, auto&& f) -> decltype(auto) {
|
|
return tag-dispatched;
|
|
};
|
|
#else
|
|
template <typename W, typename = void>
|
|
struct extend_impl : extend_impl<W, when<true>> { };
|
|
|
|
struct extend_t {
|
|
template <typename W_, typename F>
|
|
constexpr decltype(auto) operator()(W_&& w, F&& f) const;
|
|
};
|
|
|
|
constexpr extend_t extend{};
|
|
#endif
|
|
BOOST_HANA_NAMESPACE_END
|
|
|
|
#endif // !BOOST_HANA_FWD_EXTEND_HPP
|