On Wednesday, 15 August 2018 at 08:14:53 UTC, Petar Kirov
[ZombineDev] wrote:
It's not a bug, it's all about how the type system is set up.
The type of an array literal expression like `[1, 2, 3]` is
`int[]` (a slice of an array of ints), so no matter if you do:
auto readonly(T)(const(T)[] x) { return x; }
auto arr1 = [1, 2, 3];
auto arr2 = [1, 2, 3].readonly;
const arr3 = [1, 2, 3];
enum arr4 = [1, 2, 3];
static immutable arr5 = [1, 2, 3];
scope arr6 = [1, 2, 3];
In all instances the type will be `int[]` modulo type
qualifiers.
Static arrays are completely different types, that just happen
to accept
assignments from slices. Their two defining properties are:
1. Their length is fixed at compile-time, meaning that you can
do:
import std.array, std.meta;
auto x = [1, 2, 3, 4, 5].staticArray;
enum length = x.length;
pragma (msg, length);
alias seq = AliasSeq!(0, 42, length);
static foreach (i; 0 .. length) { }
static foreach (i; seq) { }
2. Where slices are reference types, static arrays are value
types which means that each assignment will copy an entire
array.
Basically they behave like a `struct { int _arr_0 = 0, _arr_1 =
1, _arr_2 = 2; }`.
https://run.dlang.io/is/iD9ydu
Thanks for the detailed explanation; it make sense now.
Mike
