Hi Mateusz, On Sat, Mar 13, 2010 at 1:23 PM, Mateusz Loskot <mateusz@loskot.net> wrote:
Christian Henning wrote:
2) I notice you saying that you're getting linker errors - that should only happen if you're taking the address of the constants somewhere - if that's a use case that you want to support, then you need a definition for the constants somewhere - suitably guarded by the right Boost.Config macros (sorry can't remember what off the top of my head).
I'm getting a compiler error with gcc 3.4.5. The compiler that comes with MinGW.
Is it compiler error or linker error?
I don't remember off the top of my head. It might have been a linker error, though. Don't have access right now to gcc.
This can be fixed, inconveniently, by adding external definition:
struct pnm_image_type : property_base<int> { typedef pnm_image_type self_type; BOOST_STATIC_CONSTANT( type, _mono_asc = 1 ); }; const int pnm_image_type::_mono_asc;
Wouldn't that create multiple instances when including this header file more than one time?
And finally, given that your constants look like enumerated values, is there actually a pressing need not to make them an anonymous enumerated type in this case?
I know about using enums for such a case. But it used to be a matter of taste since MS compiler works just fine.
Works well with in-class definition of constants from Visual C++ 7.1 (2003), but previous versions do not support it such definitions at all.
Don't think we need to worry about any Visual C++ older than 7.1. My worries are more with gcc. Regards, Christian