Function Template help

[Alex Rubinsteyn]

Hi,
I can't figure out why my function templates don't resolve properly.
Anyone here want to help me out?

[code]
---
template <typename T>
Obj* call_method (T* t, void (T::*f)())
{
(t->*f)();
return Void;
}

template <typename T, typename Ret>
Obj* call_method (T* t, Ret (T::*f)())
{
return cpp_to_hyrax((t->*f)());
}
....
I instantiate the template with:
---
T* t = new T;
Obj* o = call_method<T, void(t, &T::func);
---
T::func's signature is void().
It seems to me that the first template ought to be instantiated, but
it's the second one that wins. Any clues why?

Thanks for any help,
-Alex

[Alex Rubinsteyn]

Re: Function Template help

Also, I tried:
call_method (t, &T::func);
But the compiler tells me that call_method is ambiguous.

[Ian Collins]

Re: Function Template help

Alex Rubinsteyn wrote:

Hi,
I can't figure out why my function templates don't resolve properly.
Anyone here want to help me out?
>
[code]

Please post enough to compile.

---
template <typename T>
Obj* call_method (T* t, void (T::*f)())
{
(t->*f)();
return Void;
}
>
template <typename T, typename Ret>
Obj* call_method (T* t, Ret (T::*f)())
{
return cpp_to_hyrax((t->*f)());
}
....
I instantiate the template with:
---
T* t = new T;
Obj* o = call_method<T, void(t, &T::func);

Why not

Obj* o = call_method(t, &T::func);

Which will give you the expected result.

---
T::func's signature is void().
It seems to me that the first template ought to be instantiated, but
it's the second one that wins. Any clues why?
>

You are explicitly specifying two template types.

--
Ian Collins.

[Alex Rubinsteyn]

Re: Function Template help

Hi Ian,

Please post enough to compile.

Enough to compile...is a rather lot. I can send you the Visual Studio
project if you're interested.

Why not
>
Obj* o = call_method(t, &T::func);
>
Which will give you the expected result.

You are explicitly specifying two template types.

Sorry for the omission, but see my second post. I ended up trying to
specify the template types because call_method(t, &T::func) is (for
some reason) ambiguous. So I guess my question is, how I get the the
first call_method to be instantiated?

Thanks,
Alex

[Alex Rubinsteyn]

Re: Function Template help

Whatever the problem was, I've found a way around it by using partially
specialized functor classes instead of a function. Thanks anyways for
the help.

-Alex