Do I understand correctly that you want the memset call to be skipped for those compiler versions that have implemented value-initialization entirely correctly? Do you know exactly which compiler versions do implement value-initialization correctly?
Aleksey Gurtovoy wrote:
[...] I think we should revert to the approach of applying the workaround conditionally for the specific compilers known to be buggy, and just those -- especially if we have tests to discover these bugs should they return.
As for the specific compiler versions:
- GCC bugs #30111 and #33916 has been fixed in 4.4 and 4.2.4 correspondingly [1], [2].
So GCC 4.2.4 still needs the memset, but GCC >= 4.4.0 can do without it, right?
- MSVC bug #100744, despite being marked as "Closed, Won't Fix" [3], has actually been fixed in VC9 [4].
I'm sorry, MSVC bug #100744 is still there, even though #335987 has been fixed. VC9 deals with POD types correctly, but may not do so for non-POD aggregate class types.
- Borland bug #51854 is also reported as being fixed in build "12.0.3140.16150" [5]
Looks promising. Do you know how to do a compile-time check if Borland/Codegear build >= 12.0.3140.16150? Anyway, I wouldn't mind if the memset call in utility/value_init.hpp would become conditional, for example as follows: #ifdef BOOST_VALUE_INITIALIZATION_NEEDS_MEMSET std::memset(&x, 0, sizeof(x)); #endif What do you think? And would it be okay to you to have such a macro, BOOST_VALUE_INITIALIZATION_NEEDS_MEMSET, defined in boost/config/compiler/, for those specific compiler versions?
[1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30111#c10 [2] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33916#c12 [3] https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?Feedba... [4] https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?Feedba... [5] http://qc.embarcadero.com/wc/qcmain.aspx?rc=51854
Thanks! Kind regards, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center