On 16/04/2010 20:06, eg wrote:
On 4/16/2010 9:04 AM, Giovanni Piero Deretta wrote:
VC++ 2010 now has the iterator checking disabled by default; It is probably unlikely that you were unknowingly running with checking enabled, but that would easily explain the speedup.
Does anyone have a reference to confirm the above?
I have googled away but have found no evidence to support this. It would be great news indeed, as the burden of using _SECURE_SCL consistent/correct across a set of 3rd party libraries is too high.
"Friday, June 26, 2009 2:47 PM by Stephan T. Lavavej [MSFT] [...] Fortunately, VC10 after Beta 1 will contain "#pragma detect_mismatch", which will detect _ITERATOR_DEBUG_LEVEL mismatch deterministically at link time, instead of crashing mysteriously at run time.
Is the default in release mode now to turn SECURE_SCL off?
In VC10 after Beta 1, _ITERATOR_DEBUG_LEVEL in release mode will default to 0. And there was much rejoicing." (http://blogs.msdn.com/vcblog/archive/2009/06/23/stl-performance.aspx) I can confirm both points (see [1] and [2]). I'm really glad VS team finally listened and disabled checked iterators by default in release mode. The ODR violation check is just the cherry on the top. From what I understand, a new macro, _ITERATOR_DEBUG_LEVEL, supersedes both _SECURE_SCL and _ITERATOR_DEBUG_LEVEL. By default, _ITERATOR_DEBUG_LEVEL is set to 2 in Debug mode and to 0 in Release mode. The documentation is a bit weak, but if you search for _ITERATOR_DEBUG_LEVEL inside VC header files, you'll see the actual logic. [1] http://social.msdn.microsoft.com/Forums/en/vcpluslanguage/thread/47cac5fe-50... [2] iterator debug level preprocessor checks I've used when testing VC10, just to be sure. #if _ITERATOR_DEBUG_LEVEL == 0 #pragma message("_ITERATOR_DEBUG_LEVEL == 0") #elif _ITERATOR_DEBUG_LEVEL == 1 #pragma message("_ITERATOR_DEBUG_LEVEL == 1") #elif _ITERATOR_DEBUG_LEVEL == 2 #pragma message("_ITERATOR_DEBUG_LEVEL == 2") #endif #if _ITERATOR_DEBUG_LEVEL == 0 && _SECURE_SCL != 0 #error _SECURE_SCL != 0 while _ITERATOR_DEBUG_LEVEL == 0 #endif