That typically encloses
DLL's exported functions.
You should know,
C Language and
C++ one use different approach to function's
name mangling (i.e. altering the name of the funtion in object -or library- files), more specifically,
C++ includes in the
mangled (or
decorated) name info about the function argument types (this allows, function overloads, a
C++ feature, not available in
C language).
The mechanism allows the same header to be used by both the
C and
C++ compiler (
__cpluspls macro is defined only by the
C++ one) and works this way:
The
C compiler, ignores the
extern "C" (
__cplusplus is not defined) directive both when building the
DLL and when including the
DLL header inside an application.
The
C++ compiler, according with the
extern "C" (
__cplusplus is defined) directive:
- Produces a standard
C DLL (i.e. the function use the C language mangling scheme) when building th DLL. - consider the library as a
C DLL when the header is included in a application (you know C++ compiler is able to link with C libraries).
BTW: please don't post your question both int the
C++/MFC forum and here.
:)
Submit an article or tip