Add noexcept support to the library

[impugachev]

Why doesn't the library use noexcept anywhere? I work in an environment with no exceptions, so intrusive containers are exactly what I need, but when using Boost.Intrusive, there are some problems due to the complete lack of noexcept.

[igaztanaga]

The reason is that Intrusive was written long before noexcept was available. Any hint on which operations are most needed to be noexcept?

[impugachev]

First of all, hook constructors. Because of them, when inheriting, you have to explicitly write an empty noexcept constructor.

[igaztanaga]

Thanks for the feedback. I plan to implement firs noexcept support for the next release.

[igaztanaga]

Thanks for the report. Let me know if the support is enough or I missed something important.

[impugachev]

Many thanks! It looks like everything I need is here. I'll write if I find anything else while using it.