Does Boost.Variant require certain warnings to be disabled? The following

As recommended (thanks Steve!), I have disabled VC9's C4512 warning to get a canonical Boost.Variant example to compile (in VC9) without warnings: #pragma warning( push ) #pragma warning( disable : 4512 ) #include #pragma warning( pop ) #include <iostream> using namespace std; struct vis : public boost::static_visitor<> { void operator()( int & ) const { cout << "int" << endl; } void operator()( string & ) const { cout << "string" << endl; } }; int main( int, char * ) { boost::variant< int, string > v; boost::apply_visitor( vis(), v ); return 0; } *If* this warning is truly harmless, should this be considered a bug in Boost.Variant? Shouldn't Boost.Variant disable benign warnings in a compiler-independent way? Or at least shouldn't the Boost.Variant docs be updated? Or is this warning part of Boost.Variant's design? If so is there any way I can change my code above to compile without warnings other without explicitly suppressing warnings? Any Boost.Variant authors/maintainers care to comment? John Fearnside -----Original Message----- AMDG hfye-wila@spamex.com wrote: program generates a warning for me with VC9:

Warning 4512 is almost always harmless. It's usually caused by structs containing reference members. You're best off disabling it. In Christ, Steven Watanabe

I agree with Steve that the C4512 warning is a low-priority bug: it is easily worked around and it's only a level 4 warning. But, I must not be understanding Boost.Variant (1.35.1) because the following simple example generates several other VC9 warnings: C4345 (level 2) and C4100 (level 4): #include #ifdef BOOST_MSVC # pragma warning( push ) # pragma warning( disable : 4512 ) #endif #include #ifdef BOOST_MSVC # pragma warning( pop ) #endif #include <iostream> using namespace std; struct C1 {}; struct C2 {}; struct vis : public boost::static_visitor<> { void operator()( C1 & ) const { cout << "C1" << endl; } void operator()( C2 & ) const { cout << "C2" << endl; } }; int main( int, char * ) { boost::variant< C1, C2 > v; boost::apply_visitor( vis(), v ); return 0; } Disabling these in the manner above works but I'm hoping one of its authors/maintainers can comment on intended usage of Boost.Variant with VC9? I'm wary of disabling each warning I encounter. That makes it difficult for me to know which warnings are known to be harmless and which indicate errors in my code. BTW: By "compiler-independent way" I mean using macros to wrap compiler-specific pragmas (as above). John Fearnside -----Original Message----- AMDG hfye-wila@spamex.com wrote:

*If* this warning is truly harmless, should this be considered a bug in Boost.Variant?

I consider this a low priority bug.

Shouldn't Boost.Variant disable benign warnings in a compiler-independent way?

This warning is Visual Studio specific. In Christ, Steven Watanabe _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users