On 02/04/2011 07:49 PM, so wrote:
On Fri, 04 Feb 2011 19:33:09 +0200, Walter Bright <newshou...@digitalmars.com>
wrote:
spir wrote:
On 02/04/2011 08:34 AM, Jonathan M Davis wrote:
Slices: just one more reason why D's arrays kick the pants of other languages'
arrays...
What are the other ones?
Scope guard is another.
I would argue that transitive const is, too, but the benefits of that are
harder to see.
There are many features small in detail but superb in practice.
But still, i keep saying D has design errors as well, to me the biggest one and
maybe the main reason why D1 crowd is hostile to D2.
Const system (CS):
CS in theory a great thing, in practice it has many corner cases, simply it
doesn't worth having.
D had(still has) a chance to fix this issue in two different ways, either avoid
it or don't leave holes. This hole is not that explicit in C++ because it is
not transitive.
Transitive const brings something with it... transitivity!
Now, what i mean with this:
---
struct A {
B whatever;
bool opEquals(A a) {
return whatever == a.whatever; // just comparision, this function is const
}
bool anything(A a) {
whatever = 2; // here i have an assignment, this function is not const
return whatever;
}
}
---
It doesn't matter what signature you use for the function, compiler is aware
and will output an error when you do the opposite of the signature. If this is
the case, why do we need that signature?
Its presence just makes things complicated and with actually no reason.
---
struct A {
B whatever;
bool opEquals(A a) {
return whatever == a.whatever;
}
}
const(A) a;
A b;
bool e = a == b;
----
Thanks;
Runs with opEquals signature expected by the compiler:
struct A {
int whatever;
const bool opEquals(ref const(A) a) {
return whatever == a.whatever;
}
}
unittest {
const(A) a;
A b;
assert(a == b);
}
But what do you actually /mean/?
Denis
--
_________________
vita es estrany
spir.wikidot.com
