Guillaume Melquiond wrote: > On Tue, 13 May 2003, John Maddock wrote: > >>> One of the first things the configuration header does is: >>> >>> #if !(defined(_GLOBAL_USING) && (_GLOBAL_USING+0 > 0)) && >>> !defined(_STD) # define BOOST_NO_STDC_NAMESPACE >>> #endif >>> >>> However, during compilation, _GLOBAL_USING is defined but without >>> value and _STD is not defined, so BOOST_NO_STDC_NAMESPACE is set. >>> >>> I tried to uncover the meaning of these macros, but the only >>> explanation I found was this sentence of Peter Dimov in another >>> mail: "Dinkumware puts the names in std:: when _GLOBAL_USING is >>> #defined to 1 in <yvals.h>." >> >> Getting things correct for the dinkumware lib, is nothing short of >> Voodoo, they tend not to expose macros that we can use consistently >> - whatever patches applied. > > Your patch does not fix the problem at all. In my opinion, it can even > break some working configurations. I would rather use this > conditional expression: > > # if !(defined(_GLOBAL_USING) && (_GLOBAL_USING+0 > 0 || _CPPLIB_VER > == 310)) && !defined(_STD) > > since the test _GLOBAL_USING+0 > 0 is false although we want it true > with Dinkumware 3.10 (_CPPLIB_VER == 310 and maybe other versions but > I don't know them).
Testing _CPPLIB_VER is incorrect. AFAICS _GLOBAL_USING means "import identifiers from the global namespace into std:: via using declarations." _GLOBAL_USING can be 0 when the C library headers put identifiers in std:: and ::, as is probably the case for Intel/Linux; no further "postprocessing" is necessary. Under Windows, the C library headers do not put identifiers in std::, and _GLOBAL_USING=1 can be used as a test whether the identifiers have been imported into std:: by the <c*> headers. Note that this does not depend on _CPPLIB_VER. I think that the right thing to do here is to specifically test for the problematic configuration (i.e. __ICC && __linux) to avoid breaking Dinkumware 3.10 on other platforms. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
