Help! Redefinition Error

[CactusCat]

I have two classes in my project, both of which use the same header file which contains this struct definition:

struct vertex3D {
float X;
float Y;
float Z;
};

When I try to compile the project I get a 'struct' type redefinition error.
How can I include the above header in both classes without getting this error?

[parksie]

Use #ifndef/#define/#endif for header guarding. Search the forums...

[jim mcnamara]

like this:

#ifndef 3DVERTEX
#define 3DVERTEX 1
struct vertex3D {
	float X;
	float Y;
	float Z;
};

/* all the rest of the required stuff here..... */
#endif

It only will be included once this way.

[atjs]

You can use the '#pragma once' preprocessor directive. Put it at the top of your header files. It tells the compiler to only include the header file once.

[Zaffir]

I really should learn to use those preprocessor macros...

[parksie]

Originally posted by atjs
You can use the '#pragma once' preprocessor directive. Put it at the top of your header files. It tells the compiler to only include the header file once.

That's only for MSVC.

[CornedBee]

Originally posted by parksie
That's only for MSVC.

Which is ok if the headers are guaranteed to be only used by MSVC (like headers of MFC apps), but not if the headers contain general utility functions/classes.