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--- header-guard [May 14, 2026 at 12:59] – yanevskiv
+++ header-guard [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-# Header guard
-**Header guards** are a pattern used in C and C++ programming languages when writing header files. Header files (.h files) are files that are included in source files (.c and .cpp files) using the `#include <...>` directive. They are used to allow multiple inclusions of the same file but prevent multiple definition errors.
-Header guards follow the same general pattern.
-```c
-#ifndef __HEADER_GUARD_H__
-#define __HEADER_GUARD_H__
-// ...
-#endif
-```
-In C and C++ programming languages, `#include` is nothing but text substitution. If you include something multiple times
-## Example
-A prototypical example of a header guard is the following.
-```c
-// hello_world.h
-#ifndef __HELLO_WORLD_H__
-#define __HELLO_WORLD_H__
-struct Hello {
-    const char *text = "world";
-};
-#endif /* __HELLO_WORLD_H__ */
-```
-### Why?
-```c
-// main.c
-#include <hello_world.h>
-#include <hello_world.h>
-int main() {
-    Hello world;
-    return 0;
-}
-```