Re: What is your opinion about unsigned int u = -2 ?

Ben Bacarisse <ben@bsb.me.uk> writes:

Thiago Adams <thiago.adams@gmail.com> writes:
>

What is your opinion about this:
>
unsigned int u1 = -1;
>
Generally -1 is used to get the maximum value.

>
Yes, that's a common usage, though I prefer either -1u or ~0u.
>

Is this guaranteed to work?
>
How about this one?
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unsigned int u2 = -2;
Does it makes sense?  Maybe a warning here?

>
Warnings are almost always good, especially if they can be configured.
For example you can ask gcc to warn about converting -1 to unsigned
while leaving -1u and ~0u alone.

Ick.  That choice is exactly backwards IMO.  Converting -1 to
an unsigned type always sets all the bits.  Converting -1u to
an unsigned type can easily do the wrong thing, depending
on the target type.