c++ inline function?

Question

Why should i do something like this:

inline double square (double x) { return x*x;}

instead of

double square (double x) {          


        

Answer 1

From Wikipedia: Inline function is a function upon which the compiler has been requested to perform inline expansion. In other words, the programmer has requested that the compiler insert the complete body of the function in every place that the function is called, rather than generating code to call the function in the one place it is defined. Compilers are not obligated to respect this request.

http://en.wikipedia.org/wiki/Inline_function