Re: [boost] [type_traits] has_member_function_callable_with

Subject: Re: [boost] [type_traits] has_member_function_callable_with
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-09-15 19:07:51

On 9/15/2011 5:18 PM, Ion Gaztañaga wrote:
> Hi to all,
>
> Trying to port C++11 code (allocator_traits) to C++03 (without decltype
> support), I needed to check at compile time if a member function can be
> called with some given parameters.
>
> Typical solutions I found on the net were based on specific signatures,
> say:
>
> const bool value =
> HAS_MEMBER_FUNCTION_FUNCNAME_WITH_SIGNATURE(MyClass, (int, char*));
>
> However, it is not feasible to know the exact signature as I want to
> deal with conversions, const references, etc. Luckily, I found a very
> interesting explanation in Proto documentation:
>
> http://www.boost.org/doc/libs/1_47_0/doc/html/proto/appendices.html#boost_proto.appendices.implementation.function_arity
>
>
> Based on this, I've tried to write my solution and I'd like to share it
> here with type traits experts, in case someone knows a better solution
> (see attached example). I know I don't take into account many issues for
> a truly generic utility (const member functions, etc.) but please let me
> know if you find this example interesting.

Thanks, Ion, I definitely want to look at your solution. I also know the 
link above as it has come up before.

In TTI one can test for an exact signature but I want to pursue 
solutions based on Eric Niebler's Proto explanation and your solution 
also for future enhancements.