On Thursday, 30 January 2014 at 09:14:43 UTC, Cooler wrote:
If you want to modify the slice and make changes visible in
caller, you should use ref. If you don't care whether changes
are visible in caller, you can omit any attributes and use
plain array. This belongs to the case you are asking about. If
you don't want to change array in callee, pass it as const
qualified.
Now, after rethinking the issue I am inclining that "don't
care whether changes are visible for caller" is not very
wrong, but not very good design. Ideally it should be
specified to avoid unexpected problems to pop up. So yes, it
is better to qualify array.
Another point. This casino games of whether changes would be
visible or not is direct consequence of how slices are
implemented (and how runtime service them). Remember, that
many features in D work in a strange way not because of wise
design but as a consequence of not fully thought design (like
array). As a result, some features work in not best way they
should. Although many folks in newsgroups would eagerly say
that you don't understand the lang, it wouldn't make a bad
design a good one.
Please stop explain me how fun3() works. I know that.
This is first problem. You are being explained what is the
*purpose* of the fun3() but you repeatedly fail to accept it.
One of the main idea of D is that things must work as planned,
or would not compile at all.
Outcryingly wrong. Study bugzilla which shows how some things go
wrong and read DIPs to learn that there are some issues in the
language for which the communitty still struggles to formulate
good solution.
First and second variants follow this idea. But fun3() can work
not as planned on the caller side (depends on fun3() body's
implementation).
Many things can work not as intended. Please read forums,
bugzilla, etc. I bet passing array will not be the only thing you
find confusing.
The question again - may be prohibit fun3() variant?
Prohibiting code like:
void foo(int[] arr) {}
would break hell of a code and pose doubts on what happens with
arrays if so simple construction is prohibited. In addition, I
mentioned that "don't care" is probably sometimes an option.
Emitting warning here has some merits but it would be consitently
ignored (I expect).
