Decimal or hexadecimal double constants

Collaboration diagram for Decimal or hexadecimal double constants:

Defines
#define	P99_DEC_DOUBLE(SIGN, INT, FRAC, ESIGN, EXP)
	construct a double constant in decimal representation.
#define	P99_HEX_DOUBLE(SIGN, HEXINT, HEXFRAC, ESIGN, BINEXP)
	construct a double constant in hexadecimal representation.

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Detailed Description

Since not all substrings of a double constant form a valid preprocessor token, construction of double constants must be done carefully when done with macros. The macros here guarantee that this is done in a portable way.