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#include <iostream>
#include <vector>
#include <stdexcept>
 
template <typename T>
void f(const T &) { std::cout << "NO" << std::endl; }
 
template <typename T, int SFINAE = sizeof(static_cast<std::ostream &(std::ostream::*)(T)>(
	&std::ostream::operator<<))>
void f(const T &) { std::cout << "YES" << std::endl; }
 
int main() {
	typedef const char *(std::exception::*F0)() const;
 	F0 f0 = &std::exception::what;
 
	f(0);
	f("abc");
	f(static_cast<const char *>("abc"));
	f(0.);
	f(f0);
	f(std::vector<int>());
 
	return 0;
}

prog.cpp: In function 'int main()':
prog.cpp:16:5: error: call of overloaded 'f(int)' is ambiguous
  f(0);
     ^
prog.cpp:6:6: note: candidate: void f(const T&) [with T = int]
 void f(const T &) { std::cout << "NO" << std::endl; }
      ^
prog.cpp:10:6: note: candidate: void f(const T&) [with T = int; int SFINAE = 8]
 void f(const T &) { std::cout << "YES" << std::endl; }
      ^
prog.cpp:19:6: error: call of overloaded 'f(double)' is ambiguous
  f(0.);
      ^
prog.cpp:6:6: note: candidate: void f(const T&) [with T = double]
 void f(const T &) { std::cout << "NO" << std::endl; }
      ^
prog.cpp:10:6: note: candidate: void f(const T&) [with T = double; int SFINAE = 8]
 void f(const T &) { std::cout << "YES" << std::endl; }
      ^

Standard output is empty