63e88f80
 Hu Chunming
提交三方库
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
/*!
@file
Defines `boost::hana::monadic_compose`.
Copyright Louis Dionne 2013-2022
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_MONADIC_COMPOSE_HPP
#define BOOST_HANA_MONADIC_COMPOSE_HPP
#include <boost/hana/fwd/monadic_compose.hpp>
#include <boost/hana/chain.hpp>
#include <boost/hana/concept/monad.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/core/dispatch.hpp>
#include <boost/hana/functional/partial.hpp>
namespace boost { namespace hana {
namespace detail {
struct monadic_compose_helper {
template <typename F, typename G, typename X>
constexpr decltype(auto) operator()(F&& f, G&& g, X&& x) const {
using M = typename hana::tag_of<decltype(g(x))>::type;
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Monad<M>::value,
"hana::monadic_compose(f, g) requires 'g' to return a monadic value");
#endif
return hana::chain(static_cast<G&&>(g)(static_cast<X&&>(x)),
static_cast<F&&>(f));
}
};
}
//! @cond
template <typename F, typename G>
constexpr auto monadic_compose_t::operator()(F&& f, G&& g) const {
return hana::partial(detail::monadic_compose_helper{},
static_cast<F&&>(f),
static_cast<G&&>(g)
);
}
//! @endcond
}} // end namespace boost::hana
#endif // !BOOST_HANA_MONADIC_COMPOSE_HPP
|
