Question 11.17

I'm trying to use the ANSI ``stringizing'' preprocessing operator `#' to insert the value of a symbolic constant into a message, but it keeps stringizing the macro's name rather than its value.

You can use something like the following two-step procedure to force a macro to be expanded as well as stringized:

	#define Str(x) #x
	#define Xstr(x) Str(x)
	#define OP plus
	char *opname = Xstr(OP);

This code sets opname to "plus" rather than "OP".

An equivalent circumlocution is necessary with the token-pasting operator ## when the values (rather than the names) of two macros are to be concatenated.

References: ANSI Sec. 3.8.3.2, Sec. 3.8.3.5 example
ISO Sec. 6.8.3.2, Sec. 6.8.3.5

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