C++ include and import difference
#import
is a Microsoft-specific thing, apparently for COM or .NET stuff only.
#include
is a standard C/C++ preprocessor statement, used for including header (or occasionally other source code) files in your source code file.
Import in VC++: #import
is for type libraries or .tlbs (COM stuff).
The content of the type library is converted into C++ classes, mostly describing the COM interfaces for you automatically, and then it is included into your file.
The #import
directive was introduced by Microsoft as an extension to the C++ language. You can read about it at this MSDN article.
The #import
directive is also used with .NET / CLI stuff.
Import in gcc:
The import in gcc is different from the import in VC++. It is a simple way to include a header at most once only. (In VC++ and GCC you can do this via #pragma
once as well)
The #import
directive was officially undeprecated by the gcc team in version 3.4 and works fine 99% of the time in all previous versions of gcc which support
Include: #include
is for mostly header files, but to prepend the content to your current file. #include
is part of the C++ standard. You can read about it at this MSDN article.