Inline function:

It is a function without prototype. The function is defined above main. The function should  be  declared  above  main  function.                 

Declaring  the  function  as  inline  will  increase  the performance, but it is usually used for small functions.   It reduces the memory requirement. Inline function must have return statement in the function at the same it need not have return type. All other function sub program or must definition and prototype.

inline int f_ref(int x, int  y)

{ return (x+y); // Inline function can return statement without return type.

}

void main( )

{

int a, b;

f_ref(a, b);

}