Specifies if a header file may be included more than once in the same source file.

This pragma is compatible with the following platform targets:

68K

PowerPC

NEC V800

Intel x86

MIPS

Embedded 68K

Use this pragma to ensure that the compiler includes header files only once in a source file. This pragma is especially useful in precompiled header files.

There are two versions of this pragma: #pragma once and #pragma once on. Use #pragma once in a header file to ensure that the header file is included only once in a source file. Use #pragma once on in a header file or source file to insure that any file is included only once in a source file.

This pragma does not correspond to an option in any settings panel. By default this option is off.