[inetknght]

Throw specifications do not change function call binding behavior.

Move constructor and move operator will bind to an R-value reference if the move constructor or move operators are available. Conversely, if those functions which declare to not throw anything do end up throwing something then the result is std::terminate.

The only things that determine whether to use a move or copy is whether the reference is an R-value and whether the source or destination is const.

You can declare a {const R-value move operator (not a constructor) for the left-hand} and/or {const R-value move operator or constructor for the right-hand side} of the argument. But you won't be able to modify anything not marked mutable. You shouldn't do that though: that's a sure way to summon nasal demons. That said, I see it fairly often from less experience engineers, particularly when copy-pasting a copy operator intending to modify it for a move operator.