On 7/26/2011 5:58 PM, Jeffrey Lee Hellrung, Jr. wrote:
On Tue, Jul 26, 2011 at 2:25 PM, Edward Diener<eldiener@tropicsoft.com>wrote:
On 7/26/2011 5:03 PM, Jeffrey Lee Hellrung, Jr. wrote:
On Tue, Jul 26, 2011 at 1:19 PM, Noah Roberts<roberts.noah@gmail.com**
wrote: [...]
One thing that I think is missing is the option to check for a named
callable within a type. For example, one might want to use enable_if style concept checking. So long as a type has function 'xxx' that takes arguments of type x,y,and z, and returns something convertible to type A, the concept is obeyed. I don't believe this can be done with C++03, but with C++1X I was able to do something using decltype.
[...]
Actually, you can approximate it pretty well in C++03 (using derivation and using tricks) to the point that I think it will work pretty much as you expect except for nullary member functions, where your queries must be more restrictive. This is a useful query, but I believe Edward has decided it to be outside the scope of TTI.
I am not sure what the OP means by 'named callable". If it can be introspected within the type I can consider whether it can be done or not.
I think you missed the convertibility requirement(s).
TTI needs an exact signature.
This is something more along the lines of Frederic Bron's Type Traits Extension, I think.
That deals with operators for a type in general. I have a feeling that the OP was interested in determining whether a class was a function object for some parameter(s).