FM / hof

/usr/include/boost/hof

Name	Size	Mode	Actions
detail/	-	0755	rm
alias.hpp	5552	0644	edit dl rm
always.hpp	4261	0644	edit dl rm
apply.hpp	8363	0644	edit dl rm
apply_eval.hpp	4428	0644	edit dl rm
arg.hpp	3148	0644	edit dl rm
capture.hpp	5419	0644	edit dl rm
combine.hpp	3877	0644	edit dl rm
compose.hpp	5042	0644	edit dl rm
config.hpp	6149	0644	edit dl rm
construct.hpp	8774	0644	edit dl rm
decay.hpp	1790	0644	edit dl rm
decorate.hpp	6329	0644	edit dl rm
eval.hpp	2400	0644	edit dl rm
first_of.hpp	7100	0644	edit dl rm
fix.hpp	6314	0644	edit dl rm
flip.hpp	2690	0644	edit dl rm
flow.hpp	5060	0644	edit dl rm
fold.hpp	5000	0644	edit dl rm
function.hpp	3129	0644	edit dl rm
function_param_limit.hpp	1658	0644	edit dl rm
identity.hpp	1884	0644	edit dl rm
if.hpp	3314	0644	edit dl rm
implicit.hpp	4041	0644	edit dl rm
indirect.hpp	3268	0644	edit dl rm
infix.hpp	6043	0644	edit dl rm
is_invocable.hpp	1706	0644	edit dl rm
is_unpackable.hpp	3341	0644	edit dl rm
lambda.hpp	6458	0644	edit dl rm
lazy.hpp	8729	0644	edit dl rm
lift.hpp	3752	0644	edit dl rm
limit.hpp	3817	0644	edit dl rm
match.hpp	3331	0644	edit dl rm
mutable.hpp	1988	0644	edit dl rm
pack.hpp	12747	0644	edit dl rm
partial.hpp	8307	0644	edit dl rm
pipable.hpp	6227	0644	edit dl rm
placeholders.hpp	13799	0644	edit dl rm
proj.hpp	7517	0644	edit dl rm
protect.hpp	2145	0644	edit dl rm
repeat.hpp	4184	0644	edit dl rm
repeat_while.hpp	5154	0644	edit dl rm
result.hpp	3644	0644	edit dl rm
returns.hpp	8607	0644	edit dl rm
reveal.hpp	12187	0644	edit dl rm
reverse_fold.hpp	5271	0644	edit dl rm
rotate.hpp	2576	0644	edit dl rm
static.hpp	2395	0644	edit dl rm
tap.hpp	2118	0644	edit dl rm
unpack.hpp	5588	0644	edit dl rm
unpack_sequence.hpp	1810	0644	edit dl rm
version.hpp	679	0644	edit dl rm

Edit: /usr/include/boost/hof/first_of.hpp (7100B)

/*=============================================================================
    Copyright (c) 2012 Paul Fultz II
    first_of.h
    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
==============================================================================*/

#ifndef BOOST_HOF_GUARD_FUNCTION_CONDITIONAL_H
#define BOOST_HOF_GUARD_FUNCTION_CONDITIONAL_H

/// first_of
/// ========
/// 
/// Description
/// -----------
/// 
/// The `first_of` function adaptor combines several functions together. If
/// the first function can not be called, then it will try to call the next
/// function. This can be very useful when overloading functions using
/// template constraints(such as with `enable_if`).
/// 
/// Note: This is different than the [`match`](match.md) function adaptor, which
/// can lead to ambiguities. Instead, `first_of` will call the first function
/// that is callable, regardless if there is another function that could be
/// called as well.
/// 
/// Synopsis
/// --------
/// 
///     template<class... Fs>
///     constexpr first_of_adaptor<Fs...> first_of(Fs... fs);
/// 
/// Requirements
/// ------------
/// 
/// Fs must be:
/// 
/// * [ConstInvocable](ConstInvocable)
/// * MoveConstructible
/// 
/// Example
/// -------
/// 
///     #include <boost/hof.hpp>
///     #include <iostream>
///     using namespace boost::hof;
/// 
///     struct for_ints
///     {
///         void operator()(int) const
///         {
///             printf("Int\n");
///         }
///     };
/// 
///     struct for_floats
///     {
///         void operator()(float) const
///         {
///             printf("Float\n");
///         }
///     };
/// 
///     int main() {
///         first_of(for_ints(), for_floats())(3.0);
///     }
/// 
/// This will print `Int` because the `for_floats` function object won't ever be
/// called. Due to the conversion rules in C++, the `for_ints` function can be
/// called on floats, so it is chosen by `first_of` first, even though
/// `for_floats` is a better match.
/// 
/// So, the order of the functions in the `first_of_adaptor` are very important
/// to how the function is chosen.
/// 
/// References
/// ----------
/// 
/// * [POO51](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0051r2.pdf) - Proposal for C++
///   Proposal for C++ generic overload function
/// * [Conditional overloading](<Conditional overloading>)
///

#include <boost/hof/reveal.hpp>
#include <boost/hof/detail/compressed_pair.hpp>
#include <boost/hof/detail/callable_base.hpp>
#include <boost/hof/detail/delegate.hpp>
#include <boost/hof/detail/join.hpp>
#include <boost/hof/detail/seq.hpp>
#include <boost/hof/detail/make.hpp>
#include <boost/hof/detail/static_const_var.hpp>

namespace boost { namespace hof {

namespace detail {

template<class F1, class F2>
struct basic_first_of_adaptor : F1, F2
{
    BOOST_HOF_INHERIT_DEFAULT(basic_first_of_adaptor, F1, F2)

template<class A, class B,
        BOOST_HOF_ENABLE_IF_CONVERTIBLE(A, F1),
        BOOST_HOF_ENABLE_IF_CONVERTIBLE(B, F2)>
    constexpr basic_first_of_adaptor(A&& f1, B&& f2)
    noexcept(BOOST_HOF_IS_NOTHROW_CONSTRUCTIBLE(F1, A&&) && BOOST_HOF_IS_NOTHROW_CONSTRUCTIBLE(F2, B&&))
    : F1(BOOST_HOF_FORWARD(A)(f1)), F2(BOOST_HOF_FORWARD(B)(f2))
    {}

template<class X,
        class=typename std::enable_if<
        BOOST_HOF_IS_CONVERTIBLE(X, F1) && 
        BOOST_HOF_IS_DEFAULT_CONSTRUCTIBLE(F2)
    >::type>
    constexpr basic_first_of_adaptor(X&& x) 
    BOOST_HOF_NOEXCEPT_CONSTRUCTIBLE(F1, X&&)
    : F1(BOOST_HOF_FORWARD(X)(x))
    {}

template<class... Ts>
    struct select
    : std::conditional
    <
        is_invocable<F1, Ts...>::value, 
        F1,
        F2
    >
    {};

BOOST_HOF_RETURNS_CLASS(basic_first_of_adaptor);

template<class... Ts, class F=typename select<Ts...>::type>
    constexpr BOOST_HOF_SFINAE_RESULT(typename select<Ts...>::type, id_<Ts>...) 
    operator()(Ts && ... xs) const
    BOOST_HOF_SFINAE_RETURNS
    (
        BOOST_HOF_RETURNS_STATIC_CAST(const F&)(*BOOST_HOF_CONST_THIS)(BOOST_HOF_FORWARD(Ts)(xs)...)
    );
};

template <class F1, class F2>
constexpr const F1& which(std::true_type, const F1& f1, const F2&) noexcept
{ 
    return f1; 
}

template <class F1, class F2>
constexpr const F2& which(std::false_type, const F1&, const F2& f2) noexcept
{ 
    return f2; 
}

template<class F1, class F2>
struct conditional_kernel : compressed_pair<F1, F2>
{
    typedef compressed_pair<F1, F2> base;
    BOOST_HOF_INHERIT_CONSTRUCTOR(conditional_kernel, base)

template<class... Ts>
    struct select
    : std::conditional
    <
        is_invocable<F1, Ts...>::value, 
        F1,
        F2
    >
    {};

BOOST_HOF_RETURNS_CLASS(conditional_kernel);

template<class... Ts, class PickFirst=is_invocable<F1, Ts...>>
    constexpr BOOST_HOF_SFINAE_RESULT(typename select<Ts...>::type, id_<Ts>...) 
    operator()(Ts && ... xs) const
    BOOST_HOF_SFINAE_RETURNS
    (
        boost::hof::detail::which(
            BOOST_HOF_RETURNS_CONSTRUCT(PickFirst)(),
            BOOST_HOF_MANGLE_CAST(const F1&)(BOOST_HOF_CONST_THIS->first(xs...)),
            BOOST_HOF_MANGLE_CAST(const F2&)(BOOST_HOF_CONST_THIS->second(xs...))
        )
        (BOOST_HOF_FORWARD(Ts)(xs)...)
    );
};
}

template<class F, class... Fs>
struct first_of_adaptor 
: detail::conditional_kernel<F, BOOST_HOF_JOIN(first_of_adaptor, Fs...) >
{
    typedef first_of_adaptor fit_rewritable_tag;
    typedef BOOST_HOF_JOIN(first_of_adaptor, Fs...) kernel_base;
    typedef detail::conditional_kernel<F, kernel_base > base;

BOOST_HOF_INHERIT_DEFAULT(first_of_adaptor, base)

template<class X, class... Xs, 
        BOOST_HOF_ENABLE_IF_CONSTRUCTIBLE(base, X, kernel_base), 
        BOOST_HOF_ENABLE_IF_CONSTRUCTIBLE(kernel_base, Xs...)>
    constexpr first_of_adaptor(X&& f1, Xs&& ... fs) 
    noexcept(BOOST_HOF_IS_NOTHROW_CONSTRUCTIBLE(base, X&&, kernel_base) && BOOST_HOF_IS_NOTHROW_CONSTRUCTIBLE(kernel_base, Xs&&...))
    : base(BOOST_HOF_FORWARD(X)(f1), kernel_base(BOOST_HOF_FORWARD(Xs)(fs)...))
    {}

template<class X, class... Xs, 
        BOOST_HOF_ENABLE_IF_CONSTRUCTIBLE(base, X)>
    constexpr first_of_adaptor(X&& f1) 
    BOOST_HOF_NOEXCEPT_CONSTRUCTIBLE(base, X&&)
    : base(BOOST_HOF_FORWARD(X)(f1))
    {}

struct failure
    : failure_for<F, Fs...>
    {};
};

template<class F>
struct first_of_adaptor<F> : F
{
    typedef first_of_adaptor fit_rewritable_tag;
    BOOST_HOF_INHERIT_CONSTRUCTOR(first_of_adaptor, F);

struct failure
    : failure_for<F>
    {};
};

template<class F1, class F2>
struct first_of_adaptor<F1, F2> 
: detail::conditional_kernel<F1, F2>
{
    typedef detail::conditional_kernel<F1, F2> base;
    typedef first_of_adaptor fit_rewritable_tag;
    BOOST_HOF_INHERIT_CONSTRUCTOR(first_of_adaptor, base);

struct failure
    : failure_for<F1, F2>
    {};
};

BOOST_HOF_DECLARE_STATIC_VAR(first_of, detail::make<first_of_adaptor>);

}} // namespace boost::hof

#endif

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