composite.md L8 conflates T[] (dynamic slice) with T[N] (fixed-size array)

[davidfrogley]

Summary

Web/src/docs/types/composite.md:8 describes T[] and T[N] together as "A fixed-size slice of N elements of type T":

| T[], T[N] | A fixed-size slice of N elements of type T |

T[N] is a fixed-size array, but T[] is a dynamic-length slice — the runtime layout is {data: *T, length: uint} and length is a runtime value, not a compile-time constant. The two forms have different semantics and the table description fits only the second.

Compiler reality

Rux/Include/Rux/Type.h:40 defines Kind::Slice with inner[0] as the element type and no compile-time length. The stdlib relies on the dynamic case throughout — e.g. Std/Src/String.rux:39:

func From(slice: char8[]) -> String {
    let len = slice.length;       // runtime field, not a compile-time constant
    ...
}

If T[] were really fixed-size-N, slice.length wouldn't be a meaningful runtime read.

Suggested fix

Split the row, or keep one row but name both behaviors:

| T[] | A dynamic-length slice (data pointer + runtime length) |
| T[N] | A fixed-size array of N elements of type T |

or:

| T[], T[N] | A slice (T[], dynamic length) or fixed-size array (T[N]) of T |