Mantis 2140

P1800-2008/D4, Section 21.5.1

Clarify white space stripping around macro arguments

In Section 21.5.1

CHANGE

Each actual argument is substituted for the corresponding formal argument literally. Therefore, when an expression is used as an actual argument, the expression will be substituted in its entirety. This may cause an expression to be evaluated more than once if the formal argument was used more than once in the macro text.

TO

Each actual argument is substituted for the corresponding formal argument literally. Leading and trailing white space around the actual argument shall be stripped off, except for a single white space following an escaped identifier. Therefore, Since when an expression is used as an actual argument, the expression will be substituted in its entirety,. Tthis may cause an expression to be evaluated more than once if the formal argument was used more than once in the macro text.