Menu
I searched the site but did not find the answer I was looking for so here is a really quick question.
I am trying to do something like that :
#ifdef _WIN32 || _WIN64 #include <conio.h> #endif How can I do such a thing? I know that _WIN32 is defined for both 32 and 64 bit windows so I would be okay with either for windows detection. I am more interested in whether I can use logical operators like that with preprocessor directives, and if yes how, since the above does not work.
Compiling with gcc I get :
warning: extra tokens at end of #ifdef directive , and it basically just takes the first MACRO and ignores the rest.
373
Explanation: True, After preprocessing all the macro in the program are removed.
Macro: a word defined by the #define preprocessor directive that evaluates to some other expression. Preprocessor directive: a special #-keyword, recognized by the preprocessor. Show activity on this post. preprocessor modifies the source file before handing it over the compiler.
#ifdef: It returns true if a certain macro is defined. #ifndef: It returns true if a certain macro is not defined. #if, #elif, #else, and #endif: It tests the program using a certain condition; these directives can be nested too.
Short answer yes. You can nest defines and macros like that - as many levels as you want as long as it isn't recursive.
Try:
#if defined(_WIN32) || defined(_WIN64) // do stuff #endif The defined macro tests whether or not a name is defined and lets you apply logical operators to the result.
175
You must use #if and special operator defined
23
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
