mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-05-28 23:34:49 -05:00

They were there to work around that annoying feature of VS's preprocessor when it expands __VA_ARGS__ into the argument list of another macro. But I've just thought of a workaround that I can apply in testcrypt.c itself, so that those parens don't have to appear in every function definition in the header file. The trick is, instead of writing destination_macro(__VA_ARGS__) you instead write JUXTAPOSE(destination_macro, (__VA_ARGS__)) where JUXTAPOSE is defined to be a macro that simply expands its two arguments next to each other: #define JUXTAPOSE(first, second) first second This works because the arguments to JUXTAPOSE get macro-expanded _before_ passing them to JUXTAPOSE itself - the same reason that the standard tricks with STR_INNER and CAT_INNER work (as seen in defs.h here). So this defuses the magic behaviour of commas expanded from __VA_ARGS__, and causes the destination macro to get all its arguments in the expected places again.