Re: [boost] [functional] Interested in can_be_called<F, Sig> metafunction?

Subject: Re: [boost] [functional] Interested in can_be_called<F, Sig> metafunction?
From: TONGARI (tongari95_at_[hidden])
Date: 2012-11-04 08:27:28

2012/11/4 TONGARI <tongari95_at_[hidden]>

> Hi there,
>
> I've used this metafunction for some time, and it just fitted my need.
> Recently, I make up my mind to complete it, willing to put it in public.
>
> Synopsis
> --------------
> can_be_called<F, Sig>
>
> F
>      Any callable type to test, even member-function ptr.
> Sig
>      The desired calling signature, function-type only.
>
> Example
> -------------
> struct X;
>
> struct F
> {
>     void operator()();
> };
>
> can_be_called<void(int), void(char)>::type // mpl::true_
> can_be_called<int(), void()>::type // mpl::true_, return val can always be
> discarded
> can_be_called<int(), int&()>::type // mpl::false_, cannot return as
> reference
> can_be_called<void(int&), void(int)>::type // mpl::false_, cannot accept
> rvalue
> can_be_called<void(), void(*)()>::type // compile error, "void(*)()" not a
> function-type
> can_be_called<F, void()>::type // mpl::true_
> can_be_called<F const, void()>::type // mpl::false_, F::operator() is
> non-const
> can_be_called<void(X::*)(), void()>::type // mpl::true_, only the
> signature part is concerned
> can_be_called<void(X::*)(), void(X*)>::type // mpl::false_, implicit
> 'this' arg not accounted
>
> Repository
> ----------------
> https://github.com/jamboree/boost.functional
>
> test files provided, compile well on g++ 4.7.1 & clang 3.2
>
> No docs are written (yet), if you're interested, please let me know and
> I'll prepare for review or something...
>
> Comments are welcome :)
>

Forgot to mention that there are 2 implementations provided, unlimited &
limited, limited one can be used w/o variadic template support and has a
function-arity limit defined by BOOST_CAN_BE_CALLED_MAX_ARITY.

It's shipped with preprocessed headers.