Re: [Boost-users] enable_if and multiple partial specializations

On Fri, Apr 8, 2011 at 9:59 AM, Gennadiy Rozental wrote:

Hi,

It's late and I might be missing something, but I can't figure out how can I use enable_if to disambiguate 2 partial specializations where one is subcase of another one:

#include #include #include

#include <iostream>

template struct M { static void foo() { std::cout << "generic" << std::endl; } };

template<typename T> struct M::type> { static void foo() { std::cout << "scalar" << std::endl; } };

template<typename T> struct M::type> { static void foo() { std::cout << "enum" << std::endl; } };

struct S {}; enum FOO { FOO1, FOO2 };

int main() { M<S>::foo(); M<int>::foo(); M<FOO>::foo(); }

---------------

M<FOO>::foo() fails to compile due to ambiguity.

Any pointers? Or How to get what I want?

I'm assuming the problem is that the scalar case is also true for the enum case? On that basis, could you not us an enabler that asks if it is scalar && ! enum? - Rob. (That's just off the cuff - I 'spect a proper expert will be along soon!)