1 #ifndef BOOST_MP11_BIND_HPP_INCLUDED 2 #define BOOST_MP11_BIND_HPP_INCLUDED 3 4 // Copyright 2017, 2018 Peter Dimov. 5 // 6 // Distributed under the Boost Software License, Version 1.0. 7 // 8 // See accompanying file LICENSE_1_0.txt or copy at 9 // http://www.boost.org/LICENSE_1_0.txt 10 11 #include <boost/mp11/algorithm.hpp> 12 #include <boost/mp11/utility.hpp> 13 #include <cstddef> 14 15 namespace boost 16 { 17 namespace mp11 18 { 19 20 // mp_bind_front 21 template<template<class...> class F, class... T> struct mp_bind_front 22 { 23 // the indirection through mp_defer works around the language inability 24 // to expand U... into a fixed parameter list of an alias template 25 26 template<class... U> using fn = typename mp_defer<F, T..., U...>::type; 27 }; 28 29 template<class Q, class... T> using mp_bind_front_q = mp_bind_front<Q::template fn, T...>; 30 31 // mp_bind_back 32 template<template<class...> class F, class... T> struct mp_bind_back 33 { 34 template<class... U> using fn = typename mp_defer<F, U..., T...>::type; 35 }; 36 37 template<class Q, class... T> using mp_bind_back_q = mp_bind_back<Q::template fn, T...>; 38 39 // mp_arg 40 template<std::size_t I> struct mp_arg 41 { 42 template<class... T> using fn = mp_at_c<mp_list<T...>, I>; 43 }; 44 45 using _1 = mp_arg<0>; 46 using _2 = mp_arg<1>; 47 using _3 = mp_arg<2>; 48 using _4 = mp_arg<3>; 49 using _5 = mp_arg<4>; 50 using _6 = mp_arg<5>; 51 using _7 = mp_arg<6>; 52 using _8 = mp_arg<7>; 53 using _9 = mp_arg<8>; 54 55 // mp_bind 56 template<template<class...> class F, class... T> struct mp_bind; 57 58 namespace detail 59 { 60 61 template<class V, class... T> struct eval_bound_arg 62 { 63 using type = V; 64 }; 65 66 template<std::size_t I, class... T> struct eval_bound_arg<mp_arg<I>, T...> 67 { 68 using type = typename mp_arg<I>::template fn<T...>; 69 }; 70 71 template<template<class...> class F, class... U, class... T> struct eval_bound_arg<mp_bind<F, U...>, T...> 72 { 73 using type = typename mp_bind<F, U...>::template fn<T...>; 74 }; 75 76 template<template<class...> class F, class... U, class... T> struct eval_bound_arg<mp_bind_front<F, U...>, T...> 77 { 78 using type = typename mp_bind_front<F, U...>::template fn<T...>; 79 }; 80 81 template<template<class...> class F, class... U, class... T> struct eval_bound_arg<mp_bind_back<F, U...>, T...> 82 { 83 using type = typename mp_bind_back<F, U...>::template fn<T...>; 84 }; 85 86 } // namespace detail 87 88 template<template<class...> class F, class... T> struct mp_bind 89 { 90 #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, == 1915 ) 91 private: 92 93 template<class... U> struct _f { using type = F<typename detail::eval_bound_arg<T, U...>::type...>; }; 94 95 public: 96 97 template<class... U> using fn = typename _f<U...>::type; 98 99 #else 100 101 template<class... U> using fn = F<typename detail::eval_bound_arg<T, U...>::type...>; 102 103 #endif 104 }; 105 106 template<class Q, class... T> using mp_bind_q = mp_bind<Q::template fn, T...>; 107 108 } // namespace mp11 109 } // namespace boost 110 111 #endif // #ifndef BOOST_MP11_BIND_HPP_INCLUDED 112