why won't template deduction work in this situation

[nvrmnd]

The two anonymous objects constructed at main() inside the call to print()
requires me to supply the template arguments but it can be deduced ? right ?

GCC says :
error: missing template arguments before '(' token

#include <iostream>
using namespace std;

template <typename F>
void print( F f )
{
    cout << f() << endl;
}

template <typename T>
struct Val {
    Val( T val ) : val(val) { }
    T operator() () const { return val; };
    
    T val;
};

int main()
{
    print( Val(3) );               // << here
    print( Val("Hello World") );   // << here
    return 0;
}

[keskiverto]

Can not deduce. 'Val' is not a typename. Val<int> is a typename.

std::pair has a std::make_pair helper though.

template <typename T>
Val<T> makeVal( T t )
{
  return Val<T>(t);
}

// ...
makeVal(3) // this is ok, it calls 'makeVal' with T=int