static template functions in a class

Question

How do I make the following function inside a class and then access this function from main? My class is just a collection of a bunch of static functions.

template<typename T> double foo(vector<T> arr); 

Answer 1

Define the function in the .h file.

Works fine for me

a.h

#include <vector> #include <iostream>  using namespace std; class A { public: template< typename T>     static double foo( vector<T> arr );  };  template< typename T> double A::foo( vector<T> arr ){ cout << arr[0]; } 

main.cpp

#include "a.h" int main(int argc, char *argv[]) {     A a;     vector<int> arr;     arr.push_back(1);     A::foo<int> ( arr ); } 

 

Answer 2

You make a template class:

template<typename T> class First { public:     static  double foo(vector<T> arr) {}; }; 

Also note that you should pass vector by reference, or in your case, also const reference would do the same.

template<typename T> class First { public:     static  double foo(const vector<T>& arr) {}; }; 

You can then call the function like:

First<MyClass>::foo(vect);