Is there a standard #include convention for C++?

Question

This is a rather basic question, but it\'s one that\'s bugged me for awhile.

My project has a bunch of .cpp (Implementation) and .hpp (Definition) files.

I f

Answer 1

I always use the principle of least coupling. I only include a file if the current file actually needs it; if I can get away with a forward declaration instead of a full definition, I'll use that instead. My .cpp files always have a pile of #includes at the top.

Bar.h:

class Foo;

class Bar
{
    Foo * m_foo;
};

Bar.cpp:

#include "Foo.h"
#include "Bar.h"

Answer 2

Use only the minimum amount of includes needed. Useless including slows down compiling.

Also, you don't have to include a header if you just need to pointer to a class. In this case you can just use a forward declaration like:

class BogoFactory;

edit: Just to make it clear. When I said minimum amount, I didn't mean building include chains like:

a.h
#include "b.h"

b.h
#include "c.h"

If a.h needs c.h, it needs to be included in a.h of course to prevent maintenance problems.