Full name of submitter (unless configured in github; will be published with the issue): Jiang An
Reference (section label): [cpp.predefined]
Link to reflector thread (if any):
Issue description:
Discovered in cplusplus/draft#8584 (comment).
It's possible to static_assert that __LINE__ expands to a literal of expected forms since C++11 (example), or assert this at run time even in ancient C++98. And then in C++14, we introduced binary integer literals and digit separators, which allows __LINE__ to expand to a literal of a formerly unexpected form.
As a result, if an implementation switch to use the new forms of integer literals for __LINE__, some valid C++11 program may become ill-formed or have behavior changed.
Should there be an Annex C entry for this, or should we restrict the forms for __LINE__?
Suggested resolution:
Full name of submitter (unless configured in github; will be published with the issue): Jiang An
Reference (section label): [cpp.predefined]
Link to reflector thread (if any):
Issue description:
Discovered in cplusplus/draft#8584 (comment).
It's possible to
static_assertthat__LINE__expands to a literal of expected forms since C++11 (example), or assert this at run time even in ancient C++98. And then in C++14, we introduced binary integer literals and digit separators, which allows__LINE__to expand to a literal of a formerly unexpected form.As a result, if an implementation switch to use the new forms of integer literals for
__LINE__, some valid C++11 program may become ill-formed or have behavior changed.Should there be an Annex C entry for this, or should we restrict the forms for
__LINE__?Suggested resolution: