5 Lexical conventions [lex]

5.9 Preprocessing numbers [lex.ppnumber]

pp-number:
	digit
	. digit
	pp-number digit
	pp-number identifier-nondigit
	pp-number ' digit
	pp-number ' nondigit
	pp-number e sign
	pp-number E sign
	pp-number p sign
	pp-number P sign
	pp-number .
1
#
Preprocessing number tokens lexically include all integer-literal tokens ([lex.icon]) and all floating-point-literal tokens ([lex.fcon]).
2
#
A preprocessing number does not have a type or a value; it acquires both after a successful conversion to an integer-literal token or a floating-point-literal token.