Re: [boost] Formal Review: Boost Cast Library

From: Kevlin Henney (kevlin_at_[hidden])
Date: 2000-12-07 04:11:17

In message <v03110701b654be52d4c8@[153.32.222.4]>, Jesse Jones
<jejones_at_[hidden]> writes
>numeric_cast OTOH is very useful and not quite as trivial. I use something
>like it in my own code. The only question I have is whether it should throw
>or assert on failure. In my own code a failure almost always indicates a
>programmer error so I'd prefer the assert.

It should be a runtime failure rather than a debugging issue as there
are many conversions that cannot be conveniently checked ahead of use --
to do so would require near duplication of all the code that makes up
numeric_cast :->

One could also argue that there would be little point in having
numeric_cast if it trapped only in debug mode. Might as well use
static_cast and see if you get the right results in your unit tests --
if not, you have a conversion bug! ;-)

And finally, there is the point that, as a checked cast, numeric_cast is
consistent with the existing language. The example it follows closest is
dynamic_cast<T &>.

Kevlin
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