CODEWITHSUNDEEP
c++c++11templates
Elh48
Elh48

Reputation: 49

Create template function to call other functions with that functions parameters

I want to create a function like thread() function (get N parameters). I think I have to use a template like this:

template <typename Func, typename Param1, ...>
void function(params)
{

}

But for my function, I have to set a limited number of parameters. In the thread() function you can give this function N parameters. How is it possible to create a function and give the parameters same inside function params?

template <typename Func, typename Param1, typename Param2, typename Param3 = typename()>
    void Remote_function_caller(Func Function_name, Param1 P1, Param2 P2, Param3 P3 = Param3())
{
Function_name(P1, P2, P3);
}

void Tool1(int Data1, int Data2)
{

}

void Tool2(int Data1, int Data2, int Data3)
{

}

void main()
{
      // Call tool 1
      Remote_function_caller(Tool1, 5, 6);

      // Call tool 2
      Remote_function_caller(Tool2, 5, 6, 9);
}

To call Tool1 I have to enter 2 parameters but system gives an error because caller needs 3 parameters (and load that function with 3 parameters)...

Upvotes: 1

Views: 63

Answers (1)

Edgar Rokjān
Edgar Rokjān

Reputation: 17483

I suggest using variadic templates:

template<typename Func, typename... Params>
void function_caller(Func func, Params&&... params) {
    func(std::forward<Params>(params)...);
}

Short example:

#include <iostream>
#include <utility>

template<typename Func, typename... Params>
void function_caller(Func func, Params&&... params) {
    func(std::forward<Params>(params)...);
}

void foo(int x, int y) {
    std::cout << __PRETTY_FUNCTION__ << std::endl;
}

void bar(int x, int y, int z) {
    std::cout << __PRETTY_FUNCTION__ << std::endl;
}

int main() {
    function_caller(foo, 5, 6);
    function_caller(bar, 5, 6, 9);

    return 0;
}

The output is:

void foo(int, int)
void bar(int, int, int)

Upvotes: 2

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