The Config/trunk regression page currently shows some detailed information of various compiler defects regarding value-initialization: http://www.boost.org/development/tests/trunk/developer/config_.html If anyone wants to have a look at these results, please do so quickly! The output is from boost_no_complete_value_initialization::test(), which tests whether a specific compiler should have a new defect macro defined, BOOST_NO_COMPLETE_VALUE_INITIALIZATION. In a few days, I'm planning to add this definition to the Boost Config files of those compilers [Boost #4080], and then the test output will disappear automatically. According to the current test results, two compilers do an excellent job w.r.t. value-initialization: Intel (10.1, 11.0, 11.1) on Mac OS X, and GCC 4.4.3 (both on Linux and Windows). Compilers that don't completely do value-initialization include Microsoft Visual C++ (including msvc-10.0), Borland (including CodeGear 2010), Sun 5.10, and IBM XL V10.1. The MSVC defect was reported back in 2005 [Visual Studio #100744]. I recently reported the value-initialization defects I encountered on Embarcadero CodeGear [Embarcadero #83751, #83851] and IBM XL. The Windows version of Intel 11.1 doesn't do so well either, according to results from Huang-Vista-x86_32_intel. I still wonder why, because on Mac OS X, Intel does so well. GCC also has regression failures w.r.t. value-initialization, but those are only on earlier GCC versions, like gcc-4.2.4 and gcc-4.3.4. The last GCC bug in this area, AFAIK, [GCC #30111] was fixed for GCC 4.4. As far as I have seen, any compiler supports value-initialization of integers, floating point numbers and pointers correctly. However, problems occur for structs, classes, and arrays. Objects of those types may be left partially or entirely uninitialized, when they should have been value-initialized, depending on the compiler. I hope to have the test and the defect macro included with Boost 1.44. Please let me know if you have any comment or question about them. https://svn.boost.org/svn/boost/trunk/libs/config/test/boost_no_com_value_in... Kind regards, Niels References: [Boost #4080] "Various compilers need BOOST_NO_COMPLETE_VALUE_INITIALIZATION", https://svn.boost.org/trac/boost/ticket/4080 [Visual Studio #100744] "Value-initialization in new-expression", reported by Pavel Kuznetsov: https://connect.microsoft.com/VisualStudio/feedback/details/100744 [Embarcadero #83751, #83851] Two value-initialization bugs I recently reported: http://qc.embarcadero.com/wc/qcmain.aspx?d=83751 http://qc.embarcadero.com/wc/qcmain.aspx?d=83851 [GCC #30111] "Value-initialization of POD base class doesn't initialize members", reported by Jason Merrill: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30111 -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center