[config] disabling _MSC_EXTENSIONS disables win32
Hello, In visualc.hpp I found the following: #if !defined(_MSC_EXTENSIONS) && !defined(BOOST_DISABLE_WIN32) # define BOOST_DISABLE_WIN32 #endif I.e., disabling MSVC-specific exnetions (/Za) disables also WIN32, which, in turn, leads to undefined BOOST_WINDOWS. So if I try to compile my project with /Za, nothing compiles, because there're lot of places where BOOST_WINDOWS is used to select platform-dependant implementation (eg., in ASIO). But if I understand correctly, the purpose of disabling MSVC *language* extenstions is to ensure that the code is portable & standard-complient. So it seems to be incorrect to imply from this BOOST_DISABLE_WIN32. Am I wrong? Thanks.
In visualc.hpp I found the following:
#if !defined(_MSC_EXTENSIONS) && !defined(BOOST_DISABLE_WIN32) # define BOOST_DISABLE_WIN32 #endif
I.e., disabling MSVC-specific exnetions (/Za) disables also WIN32, which, in turn, leads to undefined BOOST_WINDOWS. So if I try to compile my project with /Za, nothing compiles, because there're lot of places where BOOST_WINDOWS is used to select platform-dependant implementation (eg., in ASIO). But if I understand correctly, the purpose of disabling MSVC *language* extenstions is to ensure that the code is portable & standard-complient. So it seems to be incorrect to imply from this BOOST_DISABLE_WIN32.
The point is that with /Za you can't #include windows.h or use any platform specific features, so that makes it very hard (impossible?) to compile code that is binary compatible between /Za and not /Za. I realize there are exceptions to this - particularly for libraries where the implementation is confined to an external binary - but given that most of Boost is header only, what did you expect? Regards, John
The point is that with /Za you can't #include windows.h or use any platform specific features, so that makes it very hard (impossible?) to compile code that is binary compatible between /Za and not /Za.
Ok, I see now, I jumped to conclusions too quickly... So it turns out that /Za is absolutely useless for any win-based development, which is very frustrating.
-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Igor R Sent: Wednesday, November 11, 2009 1:57 PM To: boost-users@lists.boost.org Subject: Re: [Boost-users] [config] disabling _MSC_EXTENSIONS disables win32
The point is that with /Za you can't #include windows.h or use any platform specific features, so that makes it very hard (impossible?) to compile code that is binary compatible between /Za and not /Za.
Ok, I see now, I jumped to conclusions too quickly... So it turns out that /Za is absolutely useless for any win-based development, which is very frustrating.
But NOT useless for detecting potential problems with *other* platforms. So *testing* it using /Za isn't useless, for the tiny cost (and admittedly modest likelihood of finding problems). If /Za isn't possible, then it warns that there is a significant risk it won't work on other platforms. (But not *certain* to fail because the coding may carefully cope with multiple platforms - like Boost.Filesystem). Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow@hetp.u-net.com
participants (3)
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Igor R -
John Maddock -
Paul A. Bristow