#define macros

[franklyn]

Hi all,

i'm currently working on some code and i have found macro definitions
that i have never seen before. can anyone help me and tell me what
they mean?

#define IPCV_MORPHOLOGY_PTRS( morphtype, flavor ) \
icv##morphtype##Rect_##flavor##_C1R_t \
icv##morphtype##Rect_##flavor##_C1R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C1R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C1R_p = 0; \
icv##morphtype##Rect_##flavor##_C3R_t \
icv##morphtype##Rect_##flavor##_C3R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C3R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C3R_p = 0; \
icv##morphtype##Rect_##flavor##_C4R_t \
icv##morphtype##Rect_##flavor##_C4R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C4R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C4R_p = 0; \
\
icv##morphtype##_##flavor##_C1R_t \
icv##morphtype##_##flavor##_C1R_p = 0; \
icv##morphtype##_##flavor##_C3R_t \
icv##morphtype##_##flavor##_C3R_p = 0; \
icv##morphtype##_##flavor##_C4R_t \
icv##morphtype##_##flavor##_C4R_p = 0;

I looked in some books and googled for such definitions but didn't
find anything about such "double dashs" (##). Does anyone know a
resource to find a description?

Thanks!
Frank

 

[Victor Bazarov]

i'm currently working on some code and i have found macro definitions
that i have never seen before. can anyone help me and tell me what
they mean?

#define IPCV_MORPHOLOGY_PTRS( morphtype, flavor ) \
icv##morphtype##Rect_##flavor##_C1R_t \
icv##morphtype##Rect_##flavor##_C1R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C1R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C1R_p = 0; \
icv##morphtype##Rect_##flavor##_C3R_t \
icv##morphtype##Rect_##flavor##_C3R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C3R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C3R_p = 0; \
icv##morphtype##Rect_##flavor##_C4R_t \
icv##morphtype##Rect_##flavor##_C4R_p = 0; \
icv##morphtype##Rect_GetBufSize_##flavor##_C4R_t \
icv##morphtype##Rect_GetBufSize_##flavor##_C4R_p = 0; \
\
icv##morphtype##_##flavor##_C1R_t \
icv##morphtype##_##flavor##_C1R_p = 0; \
icv##morphtype##_##flavor##_C3R_t \
icv##morphtype##_##flavor##_C3R_p = 0; \
icv##morphtype##_##flavor##_C4R_t \
icv##morphtype##_##flavor##_C4R_p = 0;

I looked in some books and googled for such definitions but didn't
find anything about such "double dashs" (##). Does anyone know a
resource to find a description?

Look for "token concatenation operator". Essentially it constructs
a new preprocessor token out of its left and right operands. IOW,
A ## B becomes AB.

V

 

[franklyn]

Hey Victor!

thanks for your quick reply! I found some stuff under "token
concatenation operator.

Cheers,
Frank