Rationale: Necessary to enable single quotes as digit separators
. Effect on original feature: Valid C++ 2011 code may fail to compile or may change meaning in this
International Standard
. For example, the following code is valid both in C++ 2011 and in
this International Standard, but the macro invocation produces different outcomes
because the single quotes delimit a character literal in C++ 2011, whereas they are digit
separators in this International Standard:
#define M(x, ...) __VA_ARGS__
int x[2] = { M(1'2,3'4, 5) };