Don't understand "#define for if-statement"

Question

I looked at the code used to port lua to a C ++ application.

I was very surprised to see this:

#define for if (false) {} else for 

I do not understand the meaning of this. It is useless for me to do something like this.

Do I need to do something with some compiler tricks or something else?

PS: The library I was looking at is luabind .

Answer 1

I saw something similar to this to reduce the compiler error, where the scope of the variable-variable has leaked beyond the scope of the for-statement.

Related: / Zc: forScope (matching stiffness in Loop Scope area) .