Why do some folks continue to add subsequent duplicate #include some duplicate header files in their projects?

Bat.h

#include <SFML/Graphics.hpp>

Pong.cpp

#include "Bat.h"
#include <SFML/Graphics.hpp>

Wasn't they paying attention?

CodePudding user response：

The idea is to include the headers that the current file depends on. E.g. in Pong.cpp, you're not obliged to know whether Bat.h (which you supposedly also included) depends on <SFML/Graphics.hpp> or on another graphics library or no graphics library at all. Since double include is something we can prevent (using include guards, #pragma once), it's not a problem to list every dependency, but it's an issue to miss one.