> On 12/11/15 13:39 +0000, Jonathan Wakely wrote: >> >> One downside of this change is that we introduce some (hopefully safe) >> ODR violations, where inline functions and templates that depend on >> _GLIBCXX_USE_C99_FOO might now be defined differently in C++98 and >> C++11 code. Previously they had the same definition, even though in >> C++11 mode the value of the _GLIBCXX_USE_C99_FOO macro might have been >> sub-optimal (i.e. the C99 features were usable, but the macro said >> they weren't). Those ODR violatiosn could be avoided if needed, by >> always using the _GLIBCXX98_USE_C99_FOO macro in code that can be >> included from either C++98 or C++11. We could still use the >> _GLIBCXX11_USE_C99_FOO macro in pure C++11 code (such as the numeric >> conversion functions) and get most of the benefit of this change. > > > This patch (relative to the previous one) would avoid the ODR > problems, by only using the C++98 macro in code that gets used in > C++98 and later, and using the _GLIBCXX11_XXX ones in code that is > never compiled as C++98 (specifically, the numeric conversion > functions). > > Maybe this is a safer, more conservative change.
I haven't tested either of your patches yet (the testsuite runs reeeeally slowly on Cygwin T___T), but I just wanted to express my approval of the proposed changes (more specifically, the second patch you posted). Also, I was not aware that we had to worry about C++03 compatibility. Sounds tedious.
