template<typename T>
class CImg {
	int problem(const T val) {
		return (int)val;
	}
};

class A{
public:	
	operator int() const{
		return 0;
	}    
};

A operator*(float a, const A &b) {
	return A();
}

int main() {
	CImg<A> a;
	A b,c;
	A d = b*c;

	return 0;
}

In function 'int main()':
Line 22: error: ambiguous overload for 'operator*' in 'b * c'
compilation terminated due to -Wfatal-errors.