Please help me...
The use of inline function in C++ is usual.But
What is the advantage of using 'inline' function ?
Can a function be forced as inline?

Inline functions are used to eliminate overheads which occur in case of calls made to normal functions. But it is a significant trade-off only when the function is restricted to 2-3 lines of code. Otherwise, the advantage is nullified by the large size of the code that is repeatedly pasted everytime the function is called.

Functions cannot be forced to be inline. They can only be suggested to be inline by using the keyword. It is for the compiler to decide whether to accede to the request ( in case the trade-off is advantageous).

Hope this helped. Google for more in-depth explanations..