Max Samukha wrote:
On Thu, 15 Oct 2009 21:55:07 -0500, Andrei Alexandrescu
<[email protected]> wrote:
I talked to Walter about T[new] today and it seems we are having a
disagreement.
I'd prefer Walter's way with a provision that array literals are
immutable and allocated statically:
immutable(int)[] a = [1, 2, 3]; // no allocation here
int[new] b = [1, 2]; // new storage is allocated and the literal is
copied there
int[] a = [1, 2, 3]; // error. dup needed
auto c = [1, 2, 3]; // c is of type immutable(int)[]
b[] = c; //b's length is changed and c's contents copied to b's
storage
auto d = [1, 2, 3].dup; // d is of type int[new]
auto e = [1, 2, 3].idup; // e is of type immutable(int)[new]
// arrays are true reference types
int[new] a = [1, 2, 3];
b = a;
a.length = 22;
assert (a.length == b.length);
This makes perfect sense to me. The rule would be:
If 'x' is T[new], then:
x = y; _always_ copies y into a {length, capacity-specified block},
unless it already is one. x is given a pointer to the start of that block.
x[] = y[]; does a memcpy, regardless of whether y is a T[new] or a T[].
