---Hi, what mean, what help it can do?

[Bill Zhao]

Hi,
I am browsing the source codes and it include the below code in a .h file
somebody can tell me what the codes below mean ?

Bill Zhao
----------------------------------
#ifdef __cplusplus
extern "C"
{
xxxxx
xxxx
.......
xxxxx

#ifdef __cplusplus
}
---------------------------------

 

[John Harrison]

Hi,
I am browsing the source codes and it include the below code in a .h
file
somebody can tell me what the codes below mean ?

Bill Zhao
----------------------------------
#ifdef __cplusplus
extern "C"
{
#endif

xxxxx
xxxx
......
xxxxx

#ifdef __cplusplus
}
#endif

It means the header declares routines and data which are written in
C++ but are callable from C or C++. Lookup __cplusplus and extern "C" in
your favourite C++ book.

john

 

[Ivan Vecerina]

I am browsing the source codes and it include the below code in a .h file
somebody can tell me what the codes below mean ? ....
#ifdef __cplusplus
extern "C"
{

<< extern "C" >> is used to tell a C++ compiler that the following
declaration/function(s)
are to be linked using C conventions (i.e. without name mangling).
This is typically used to allow a library to be used from both C and C++.
( NB: the function implementations themselves may be written
in either C or C++ ).

When a C compiler is used, << extern "C" >> would be a compile error and is
unnecessary. So the << #ifdef __cplusplus ... #endif >> is used to hide the
extern "C" from a non-C++ compiler.

Ni hao -ivan

 

[Bill Zhao]

John Harrison ??:

It means the header declares routines and data which are written in C++
but are callable from C or C++. Lookup __cplusplus and extern "C" in
your favourite C++ book.

john

thank you indeed and I can go ahead my work.
I only have a very short book of c++.

Billz

 

[jeffc]

thank you indeed and I can go ahead my work.
I only have a very short book of c++.

Maybe buy a longer book if you will be doing much more work.....