static arrays becoming value types

[Yigal Chripun]

On 20/10/2009 03:50, Walter Bright wrote:
> Currently, static arrays are (as in C) half-value types and
> half-reference types. This tends to cause a series of weird problems and
> special cases in the language semantics, such as functions not being
> able to return static arrays, and out parameters not being possible to
> be static arrays.
>
> Andrei and I agonized over this for some time, and eventually came to
> the conclusion that static arrays should become value types. I.e.,
>
> T[3]
>
> should behave much as if it were:
>
> struct ??
> {
> T[3];
> }
>
> Then it can be returned from a function. In particular,
>
> void foo(T[3] a)
>
> is currently done (as in C) by passing a pointer to the array, and then
> with a bit of compiler magic 'a' is rewritten as (*a)[3]. Making this
> change would mean that the entire array would be pushed onto the
> parameter stack, i.e. a copy of the array, rather than a reference to it.
>
> Making this change would clean up the internal behavior of types.
> They'll be more orthogonal and consistent, and templates will work better.
>
> The previous behavior for function parameters can be retained by making
> it a ref parameter:
>
> void foo(ref T[3] a)

that's good news :)