T[new]

[Walter Bright]

D has a number of subtle problems (performance and semantic) that arise 
when arrays are resized. The solution is to separate resizeable array 
types from slices. Slices will retain the old:

    T[] slice;

syntax. Resizeable arrays will be declared as:

    T[new] array;

The new expression:

    new T[10]

will return a T[new].

T[new] will implicitly convert to T[], but not the other way.

slice.length will become read-only.

Under the hood, a T[new] will be a single pointer to a library defined 
type. This library defined type will likely contain three properties:

     size_t length;
     T* ptr;
     size_t capacity;

The usual array operations will work on T[new] as well as T[].

Doing this change will:

1. fix many nasties at the edges of array semantics

2. make arrays implementable on .net

3. make clear in function signatures if the function can resize the 
array or not