[iostreams] VC8/VC9 compiler warnings

[Richard Webb <richard.webb@…>]

iostreams produces a couple of compiler warnings when built in the MS compilers using warning level 4 and/or code analysis:

boost\iostreams\detail\functional.hpp(105) : warning C4512: 'boost::iostreams::detail::member_close_operation<T>' : assignment operator could not be generated

boost\iostreams\traits.hpp(48) : warning C6334: sizeof operator applied to an expression with an operator might yield unexpected results

Noticed when running the regression tests. Some examples of the full warnings can be seen at ​http://tinyurl.com/3xe4rt

[Jonathan Turkanis]

I eliminated all but a few VC 8.0 warnings with warning level 4 in [42290], [42291], and [42293]. I could not reproduce warning C6334 on VC8.0.

[Richard Webb <richard.webb@…>]

C6334 only happens when the code analysis option is enabled (only available on some versions of visual studio - not in the express version at least).

[Jonathan Turkanis]

I have fixed a couple of additional unreferenced parameter warnings and a warning about operator, in detail/is_incrementable.hpp (see [45754])

The only remaining warnings I see are 4275, which I don't know how to fix without disabling similar warnings in user code.

I am closing this ticket now; please report any remaining warnings in a new ticket.