On 6/17/2014 1:55 AM, bearophile wrote:
Walter Bright:
But it is not uninitialized. All out parameters are default initialized to
their .init value.<
I don't agree with this opinion, as they *are* initialized.<
The documentation of Microsoft SAL2, several discussions, and some other things
I've read tell me that if you want your compiler to catch some of your bugs
statically (and optimize well) it needs to be strict.
Microsoft SAL2 is not about D, and D's 'out' has nothing to do with strictness.
Frankly, I think D's parameter classes and array slices are far simpler and more
effective than SAL2.
How much often do I need to write a function like foo?
I think it's uncommon.
I suspect that is a guess.
If this little breaking change is introduced in D, I am then forced to write foo
like this:
void foo2(out int x) { x = 0; }
Is this a price small enough to pay for that increase in strictness?
I see it as annoying and nothing to do with 'strictness'. D default initializes
all variables that don't have an explicit initializer. This is normal for D, and
is a nice convenience. There's no reason that 'out' should behave differently.
It's also a correctness feature - the default initializer is NOT always 0, and
if you're writing generic code you'd be making a mistake to use 0. You'd have to
initialize it to 'typeof(x).init', which is a good way of punishing users :-)
