Tobias Schwinger wrote:

Michael,

Michael Marcin wrote:

...

I ran into a compiler problem using the singleton library from the vault.

singleton's constructor and destructor use instance_proxy before it is defined. The trivial fix is to make the definition of the constructor and destructor inline function at the bottom of the file (i.e. after instance_proxy is defined).

Actually, that shouldn't be a problem since 'singleton' is a template and things are complete once it's instantiated.

I think the compiler is allowed to check for an incomplete type before it is instantiated. I believe this is the same problem that fusion as_vector had a while ago. http://article.gmane.org/gmane.comp.lib.boost.devel/166502

Got some code that fails to compile?

Yes, #include <boost/utility/singleton.hpp>

...

singleton_manager.hpp causes warning under msvc 8.0 in the singleton_manager::cleanup function:

warning C4706: assignment within conditional expression

for

while (!!(i = ptr_instance->ptr_first))

if this could be rewritten without much effort to silence the warning it would be nice.

Yes (where interestingly the compiler could figure out this is not a typo here because of the '!!')...

Maybe

while ((i = ptr_instance->ptr_first) != 0l)

will do the trick...

That works, or context* i = ptr_instance->ptr_first; while ( i ) { context* next = i->ptr_next; i->fnc_dtor(i); i = ptr_instance->ptr_first = next; }

...

Nit - there seems to be a lot of extraneous inline keywords for functions defined inside the class definition.

...intentionally, because some compilers (under certain configurations) distinguish between "implicit" inline and "inline by keyword".

Hmm didn't expect that since the standard says its the same as declaring it inline just after the class's closing ';' IIRC. Out of curiosity do you remember what compilers do this? Thanks, Michael Marcin