Include Guards

Include Guards

#including a file more than once during the same compilation session will most likely cause the compiler to issue error messages since definitions and declarations of the file are repeated. However, in many cases, the same file may be #included in different source file that are compiled together:

 #include "Time.h" //file Time.h itself contains #include "chrono.h"  directive#include "Date.h" //file date.h also contains #include "chrono.h"  directivevoid main() {Date d;Time t; }

In order to avoid compile time errors, every header file should have an #include guard to ensure it is scanned only once in a single compilation session:

 //file Chrono.h#ifndef CHRONO_H //is this file #included the first time during this compilation?#define CHRONO_H	true//declarations, namespace definitions, typedefs and any other stuff goes here:class Chrono { /*_*/ };#endif

If CHRONO_H is defined, the compiler ignores the contents of Chrono.h between #ifndef and #endif. The first time Chrono.h is scanned during compilation, its contents are read and CHRONO_H is defined. Any subsequent inclusion thereafter is harmless since the file contents will be ignored. Bear in mind that all standard headers have #include guards.

Share the Post:
Heading photo, Metadata.

What is Metadata?

What is metadata? Well, It’s an odd concept to wrap your head around. Metadata is essentially the secondary layer of data that tracks details about the “regular” data. The regular

XDR solutions

The Benefits of Using XDR Solutions

Cybercriminals constantly adapt their strategies, developing newer, more powerful, and intelligent ways to attack your network. Since security professionals must innovate as well, more conventional endpoint detection solutions have evolved

AI is revolutionizing fraud detection

How AI is Revolutionizing Fraud Detection

Artificial intelligence – commonly known as AI – means a form of technology with multiple uses. As a result, it has become extremely valuable to a number of businesses across

AI innovation

Companies Leading AI Innovation in 2023

Artificial intelligence (AI) has been transforming industries and revolutionizing business operations. AI’s potential to enhance efficiency and productivity has become crucial to many businesses. As we move into 2023, several