fork(1) download

copy

#include <iostream>
using namespace std;
 
//template<typename T> T f(T x = T() ) { return x; }
 
template<typename T> T f( T x) { return x; }
 
template<typename T> T f()
{
  return f<T>(T());
}
 
int main() {
 
	auto a = f();
	std::cout << a;
	return 0;
}
 

prog.cpp: In function 'int main()':
prog.cpp:15:13: error: no matching function for call to 'f()'
  auto a = f();
             ^
prog.cpp:6:24: note: candidate: template<class T> T f(T)
 template<typename T> T f( T x) { return x; }
                        ^
prog.cpp:6:24: note:   template argument deduction/substitution failed:
prog.cpp:15:13: note:   candidate expects 1 argument, 0 provided
  auto a = f();
             ^
prog.cpp:8:24: note: candidate: template<class T> T f()
 template<typename T> T f()
                        ^
prog.cpp:8:24: note:   template argument deduction/substitution failed:
prog.cpp:15:13: note:   couldn't deduce template parameter 'T'
  auto a = f();
             ^

Standard output is empty