Nesting of a preprocessor directive within a macro defn

[Henry Spencer]

In article <849 at gtenmc.UUCP> ravim at gtenmc.UUCP (Ravi Kumar Mandava) writes:
>Is nesting of a preprocessor directive within a macro definition (RHS) not
>allowed?

It is not possible.  The very first thing that happens to ANSI C source
during compilation is that backslashed newlines are stripped out, so any
"#" within the RHS is no longer at the start of a line and hence does
not begin a preprocessor directive.

(And incidentally, the result of macro expansion "is not processed as a
preprocessing directive even if it resembles one", section 3.8.3.4.)

Some old C compilers may have permitted such things, due to the vagueness
of the old definition of how the preprocessor features interacted.
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