warning using boost::variant<boost::mpl_::void_>

[Yun Zhang <yun.zhang@…>]

Using VC8, get compile warning C4345:

\boost\variant\variant.hpp(1174) : warning C4345: behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized

[Steven Watanabe]

You can safely ignore this warning. Basically, the compiler is issuing a warning because it is compliant, where previous versions of msvc were not.

[Yun Zhang <yun.zhang@…>]

Thanks for clarifying that the code is functional.

Is there a possibility that the boost header will either suppress or avoid the warning in a later release?

[Steven Watanabe]

I believe that VC9 doesn't generate this warning. It's unlikely to be suppressed in Boost in the near future, since warnings usually get low priority.

[David Sankel <camior@…>]

This warning does show up in vc10. Solution would be to add a

#ifdef _MSC_VER
#pragma warning( push )
#pragma warning( disable : 4345 )
#endif

at the top of variant.hpp and

#ifdef _MSC_VER
#pragma warning( pop )
#endif

at the bottom.

[Michael Caisse]

Please see David Sankel's comment:6 above.

Problem has resurfaced in VC10. Just love warnings letting me know that they are doing the right thing.

[Antony Polukhin]

(In [85928]) Fix MSVC warning in Boost.Variant (refs #3020)

[Antony Polukhin]

In [86650] fix for this issue was merged to release branch.