digitalmars.D - Immutable static arrays
- H. S. Teoh (21/21) Mar 16 2012 Is this a bug?
- Daniel Murphy (5/26) Mar 16 2012 This is correct. It's the same as for primitive types. Because they
- H. S. Teoh (11/21) Mar 16 2012 [...]
- Daniel Murphy (5/23) Mar 16 2012 The difference is dynamic arrays contain an indirection, static arrays
Is this a bug?
import std.stdio;
void main() {
immutable(int)[4] a;
immutable(int[4]) b;
writeln(typeid(a));
writeln(typeid(b));
}
Output:
immutable(int[4])
immutable(int[4])
So there's no tail-const type for static arrays?
More to the point, how should AA's with immutable static array keys be
implemented? The current implementation doesn't work at all because the
input static array can't be assigned to the Slot (the static array field
in Slot is completely immutable, even from the Slot ctor???).
T
--
It is widely believed that reinventing the wheel is a waste of time; but
I disagree: without wheel reinventers, we would be still be stuck with
wooden horse-cart wheels.
Mar 16 2012
"H. S. Teoh" <hsteoh quickfur.ath.cx> wrote in message
news:mailman.803.1331956296.4860.digitalmars-d puremagic.com...
Is this a bug?
import std.stdio;
void main() {
immutable(int)[4] a;
immutable(int[4]) b;
writeln(typeid(a));
writeln(typeid(b));
}
Output:
immutable(int[4])
immutable(int[4])
So there's no tail-const type for static arrays?
More to the point, how should AA's with immutable static array keys be
implemented? The current implementation doesn't work at all because the
input static array can't be assigned to the Slot (the static array field
in Slot is completely immutable, even from the Slot ctor???).
T
--
It is widely believed that reinventing the wheel is a waste of time; but
I disagree: without wheel reinventers, we would be still be stuck with
wooden horse-cart wheels.
This is correct. It's the same as for primitive types. Because they
implicitly convert to immutable, AAs should store a mutable copy. T[N]
should be handled almost the same as T.
Mar 16 2012
On Sat, Mar 17, 2012 at 02:59:55PM +1100, Daniel Murphy wrote: [...][...]So there's no tail-const type for static arrays? More to the point, how should AA's with immutable static array keys be implemented? The current implementation doesn't work at all because the input static array can't be assigned to the Slot (the static array field in Slot is completely immutable, even from the Slot ctor???).This is correct. It's the same as for primitive types. Because they implicitly convert to immutable, AAs should store a mutable copy. T[N] should be handled almost the same as T.[...] So string[immutable int[4]] should store int[4] as key? I guess I just found it strange that assigning to a string (==immutable(char)[]) field is OK, but assigning to immutable(char[4]) is not. T -- Without outlines, life would be pointless.
Mar 16 2012
"Daniel Murphy" <yebblies nospamgmail.com> "H. S. Teoh" <hsteoh quickfur.ath.cx> wrote in message news:mailman.805.1331958621.4860.digitalmars-d puremagic.com...On Sat, Mar 17, 2012 at 02:59:55PM +1100, Daniel Murphy wrote: [...]The difference is dynamic arrays contain an indirection, static arrays don't. Treat them the same as you do primitive types and they should work. (apart from compiler bugs)[...]So there's no tail-const type for static arrays? More to the point, how should AA's with immutable static array keys be implemented? The current implementation doesn't work at all because the input static array can't be assigned to the Slot (the static array field in Slot is completely immutable, even from the Slot ctor???).This is correct. It's the same as for primitive types. Because they implicitly convert to immutable, AAs should store a mutable copy. T[N] should be handled almost the same as T.[...] So string[immutable int[4]] should store int[4] as key? I guess I just found it strange that assigning to a string (==immutable(char)[]) field is OK, but assigning to immutable(char[4]) is not.
Mar 16 2012