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Specialize conditional on two functions

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This commit is contained in:
Paul
2016-02-21 09:18:09 -06:00
parent 9b9b63a617
commit 2a668fecb5
1 changed files with 26 additions and 8 deletions
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34
include/fit/conditional.hpp
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@@ -90,6 +90,14 @@ struct conditional_kernel : F1, F2
constexpr conditional_kernel(A&& f1, B&& f2) : F1(FIT_FORWARD(A)(f1)), F2(FIT_FORWARD(B)(f2))
{}
template<class X,
class=typename std::enable_if<
FIT_IS_CONVERTIBLE(X, F1) &&
FIT_IS_DEFAULT_CONSTRUCTIBLE(F2)
>::type>
constexpr conditional_kernel(X&& x) : F1(FIT_FORWARD(X)(x))
{}
template<class... Ts>
struct select
: std::conditional
@@ -100,18 +108,15 @@ struct conditional_kernel : F1, F2
>
{};
template<class... Ts>
constexpr const typename select<Ts...>::type& select_function() const
{
return *this;
}
FIT_RETURNS_CLASS(conditional_kernel);
template<class... Ts>
template<class... Ts, class F=typename select<Ts...>::type>
constexpr FIT_SFINAE_RESULT(typename select<Ts...>::type, id_<Ts>...)
operator()(Ts && ... x) const
FIT_SFINAE_RETURNS(FIT_CONST_THIS->select_function<Ts&&...>()(FIT_FORWARD(Ts)(x)...));
FIT_SFINAE_RETURNS
(
FIT_RETURNS_STATIC_CAST(const F&)(*FIT_CONST_THIS)(FIT_FORWARD(Ts)(x)...)
);
};
}
@@ -154,6 +159,19 @@ struct conditional_adaptor<F> : F
{};
};
template<class F1, class F2>
struct conditional_adaptor<F1, F2>
: detail::conditional_kernel<F1, F2>
{
typedef detail::conditional_kernel<F1, F2> base;
typedef conditional_adaptor fit_rewritable_tag;
FIT_INHERIT_CONSTRUCTOR(conditional_adaptor, base);
struct failure
: failure_for<F1, F2>
{};
};
FIT_DECLARE_STATIC_VAR(conditional, detail::make<conditional_adaptor>);
} // namespace fit