File size: 1,958 Bytes
8ae5fc5 | 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 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 | #ifndef METAL_LAMBDA_BIND_HPP
#define METAL_LAMBDA_BIND_HPP
#include "../config.hpp"
namespace metal {
/// \cond
namespace detail {
template <class lbd, class... vals>
struct _bind;
}
/// \endcond
/// \ingroup lambda
///
/// ### Description
/// Provides higher-order composition of \lambdas.
///
/// \tip{Use metal::arg<n> as a placeholder for the n-th argument.}
///
/// ### Usage
/// For any \lambdas `lbd` and `lbd_0, ..., lbd_n-1`
/// \code
/// using result = metal::bind<lbd, lbd_0, ..., lbd_n-1>;
/// \endcode
///
/// \returns: \lambda
/// \semantics:
/// If `lbd` holds \expression `f` and, likewise, `lbd_0, ..., lbd_n-1`
/// hold \expressions `f_0, ..., f_n-1`, then
/// \code
/// using result = metal::lambda<g>;
/// \endcode
/// where `g` is an \expression such that
/// \code
/// template<class... args>
/// using g = f<f_0<args...>, ...<args...>, f_n-1<args...>>;
/// \endcode
///
/// ### Example
/// \snippet lambda.cpp bind
///
/// ### See Also
/// \see lambda, invoke, arg, always
template <class lbd, class... vals>
using bind = typename detail::_bind<lbd, vals...>::type;
}
#include "../detail/sfinae.hpp"
#include "../lambda/lambda.hpp"
namespace metal {
/// \cond
namespace detail {
template <class... vals>
struct _bind_impl {
template <template <class...> class expr, template <class...> class... params>
using type =
#if defined(METAL_WORKAROUND)
call<expr, call<params, vals...>...>;
#else
expr<params<vals...>...>;
#endif
};
template <class lbd, class... vals>
struct _bind {
};
template <template <class...> class expr, template <class...> class... params>
struct _bind<lambda<expr>, lambda<params>...> {
template <class... vals>
using impl = forward<_bind_impl<vals...>::template type, expr, params...>;
using type = lambda<impl>;
};
}
/// \endcond
}
#endif
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