Re: How on earth did noexcept get through the standards process?
On 4 Apr., 21:39, Francis Glassborow wrote:
[...]
However if the body of a noexcept qualified function does not call
unqualified (i.e. noexcept(false) ) functions and does not itself throw
directly then it becomes possible to optimise its implementation by
removing checks for exceptions and preparation for handling exceptions.
And that is because it is implementation-defined whether stack
unwinding is performed or not as opposed to the violated throw()
specification case where stack unwinding is required. Did I get this
right? If so, yes, that seems to be the only advantage w.r.t.
compilation optimization.
The other and IMHO more important area is that noexcept allows us to
write generic code which can exploit and propagate the noexcept
specification as well as select between two different implementations
to maintain exception safety but also improve performance depending on
whether some type's move constructor might throw or not. Examples:
call wrappers, a growing std::vector.
SG
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