On 10/8/07, Joel de Guzman <joel@boost-consulting.com> wrote:
There's no way to detect the signature of a template function (the operator()):
Perhaps you don't need this. You only need to check if the template function operator() matches one signature in the Signatures set. I have found this nice (and very small) code from Paul Mensonides that seems to works (at least for me) http://www.mail-archive.com/boost@lists.boost.org/msg00164.html The limitation is that you have to specify the type of the function, but in our case is not a problem because we have a finite set called 'Signatures' among which to choose the operator() type. As you can see from his testing example: truct X { void operator()(void) { return; } }; struct Y { }; struct Z { template<class T> T operator()(T v) const { return v; } }; int main(void) { std::cout << has_function_call<void (X::*)(void)>::value << '\n' << has_function_call<void (Y::*)(void)>::value << '\n' << has_function_call<int (Z::*)(int) const>::value << '\n'; return 0; } It is possible to check against any operator() given that you now the signatures you are looking for. Now the challange is, given a function obect of class F, to forge a way to loop across Signatures, that are function signatures, void (void) void (void) int (int) const transform in the corresponding member signatures of class F void (F::*)(void) void (F::*)(void) int (F::*)(int) const And check each one with has_function_call() until a match is found or return an error otherwise. Easier to say then to do ;-) Marco