Using #define to include another file in C++/C

Question

I want to define a macro which includes another header file like so:

#define MY_MACRO (text) #include \"__FILE__##_inline.inl\"

So that whe

Answer 1

You cannot use __FILE__ because that is already quoted, and #include doesn't support string concatenation. But you can use macros after #include:

#define STRINGIZE_AUX(a) #a
#define STRINGIZE(a) STRINGIZE_AUX(a)
#define CAT_AUX(a, b) a##b
#define CAT(a, b) CAT_AUX(a, b)
#define MY_MACRO(file, name) STRINGIZE(CAT(file, CAT(name, _inline.inl)))
#include MY_MACRO(aaaa, qqq)

You should use the equivalent Boost.Preprocessor macros instead of CAT and STRINGIZE to prevent global namespace pollution.