Template & Template Function in C++

Template:

Templates are mechanism that is possible to use one function or class to handle many different data type by using template.

Template is a feature of C++ programming language that allows function and class to operate generic function.

Advantages:

                                i.            Template is linked at compile time.

                              ii.            Template reduces the size of code.

                            iii.            Templates are considered type-safe.

Disadvantages:

                                i.            The compiler generates additional code for each template type.

Syntax:

template  <class template_var> 

Template Function:

 

We can design a single function that operates on data of many types.

Syntax:

template  <class T>

return_type fun_name(argument type T)

{

            //Body of function with type T

}

Ex:

template<class T1>

void swap(T1 &x, T1 &y)

{

 T1 temp;

 temp =x;

 x=y;

 y=temp;

}

void main()

{

 int a=10,b=20;

 char x=’a’, y=’z’;

 float m=10.5, n=20.5;

 cout<<”After Swap : ”;

 cout<<”\n int a = ”<<a<<” int b = ”<<b;

 cout<<”\n char x = ”<<x<<” char y = ”<<y;

 cout<<”\n float m = ”<<m<<” float n = ”<<n;

 swap(a,b);

 swap(x,y);

 swap(m,n);

 cout<<”Before Swap : ”;

 cout<<”\n int a = ”<<a<<” int b = ”<<b;

 cout<<”\n char x = ”<<x<<” char y = ”<<y;

 cout<<”\n float m = ”<<m<<” float n = ”<<n;

 getch();

}

Template Function Overloading:

A template function may be overloaded either by template function or ordinary function.

template <class t1>

void display(t1 x)

{

 cout<<”Template function”<<x;

}

void display(int x)

{

 Cout<<”Explicit function”<<x;

}

void main()

{

 display(10);

 display(‘z’);

 display(10.50);

}