is it possible to make function that will accept multiple data types for given argument?

Question

Writing a function I must declare input and output data types like this:

int my_function (int argument) {}

Is it possible to make such a de

Answer 1

Your choices are

ALTERNATIVE 1

You can use templates

template <typename T> 
T myfunction( T t )
{
    return t + t;
}

ALTERNATIVE 2

Plain function overloading

bool myfunction(bool b )
{
}

int myfunction(int i )
{
}

You provide a different function for each type of each argument you expect. You can mix it Alternative 1. The compiler will the right one for you.

ALTERNATIVE 3

You can use union

union myunion
{ 
    int i;
    char c;
    bool b;
};

myunion my_function( myunion u ) 
{
}

ALTERNATIVE 4

You can use polymorphism. Might be an overkill for int , char , bool but useful for more complex class types.

class BaseType
{
public:
    virtual BaseType*  myfunction() = 0;
    virtual ~BaseType() {}
};

class IntType : public BaseType
{
    int X;
    BaseType*  myfunction();
};

class BoolType  : public BaseType
{
    bool b;
    BaseType*  myfunction();
};

class CharType : public BaseType
{
    char c;
    BaseType*  myfunction();
};

BaseType*  myfunction(BaseType* b)
{
    //will do the right thing based on the type of b
    return b->myfunction();
}

Answer 2

read this tutorial, it gives some nice examples http://www.cplusplus.com/doc/tutorial/templates/

Answer 3

#include <iostream>

template <typename T>
T f(T arg)
{
    return arg;
}

int main()
{
    std::cout << f(33) << std::endl;
    std::cout << f('a') << std::endl;
    std::cout << f(true) << std::endl;
}

output:

33
a
1

Or you can do:

int i = f(33);
char c = f('a');
bool b = f(true);

Answer 4

Use a template:

template <typename T>
T my_function(T arg) {
  // Do stuff
}

int a = my_function<int>(4);

Or just overload:

int my_function(int a) { ... }
char my_function(char a) { ... }
bool my_function(bool a) { ... }