http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55783
--- Comment #6 from David Sankel <david at stellarscience dot com> 2012-12-22 00:33:44 UTC --- I suppose which gnu extensions are, by default, enabled in the -std=c++11 mode is up for debate (one which I have no interest in). However, this program still compiles with "-pedantic". "-pedantic Issue all the warnings demanded by strict ISO C and ISO C++; reject all programs that use forbidden extensions" Allowing for these narrowing conversions would qualify as a forbidden extension. Regarding compliance, I think Johnathan's snippet is misleading. Here is the relevant surrounding text: If a program contains a violation of any diagnosable rule or an occurrence of a construct described in this Standard as “conditionally-supported” when the implementation does not support that construct, a conforming implementation shall issue at least one diagnostic message. I didn't see in the standard where it states that breaking this feature is "conditionally supported". However, it does say: If a program contains a violation of a rule for which no diagnostic is required, this International Standard places no requirement on implementations with respect to that program. Which pretty much allows gcc to do anything it wants with malformed programs. But as stated above, -pedantic should guarentee rejection.
