How to execute a piece of code only once?

Question

I have an application which has several functions in it. Each function can be called many times based on user input. However I need to execute a small segment of the code wi

Answer 1

Using C++11 -- use the std::call_once

#include 

std::once_flag onceFlag;

{
    ....
    std::call_once ( onceFlag, [ ]{ /* my code body here runs only once */ } );
    ....
}