From http://stackoverflow.com/questions/14664589/variadic-template-code-compiles-on-gcc-4-6-but-not-on-clang-or-gcc-4-7 :

class Test {
    public:
    template <class... A2> void print (void(*function)(A2..., float, double)) {

    }
};

void test_print (int a, float b, double c) { }

int main () {
    Test test;
    test.print<int> (&test_print);
}

Fails with

source.cpp:14:33: note: candidate is:
source.cpp:3:33: note: template<class ... A2> void Test::print(void (*)(A2 ..., float, double))
source.cpp:3:33: note:   template argument deduction/substitution failed:
source.cpp:14:33: note:   mismatched types 'float' and 'int'

GCC does apparently not substitute the explicitly specified arguments of "A2" before attempting the argument deduction.