Questions about GC

[Thomas]

thank you, do you know how to reuse an array? it seems to reset 
the capacity when you set the length to 0, so it reallocates when 
you append to it
```
import std.stdio;
import std.format;

void main()
{
     int[] xs;

     foreach (i ; 0..3)
     {
         format("1: length:%s capacity:%s ptr:%s",xs.length, 
xs.capacity, xs.ptr).writeln;
         xs.length = 0;
         format("2: length:%s capacity:%s ptr:%s",xs.length, 
xs.capacity, xs.ptr).writeln;
         xs ~= i;
         format("3: length:%s capacity:%s ptr:%s",xs.length, 
xs.capacity, xs.ptr).writeln;
         writeln("------------------------");
     }
}
```

gives me
```
1: length:0 capacity:0 ptr:null
2: length:0 capacity:0 ptr:null
3: length:1 capacity:3 ptr:72DECA101020
------------------------
1: length:1 capacity:3 ptr:72DECA101020
2: length:0 capacity:0 ptr:72DECA101020
3: length:1 capacity:3 ptr:72DECA101060
------------------------
1: length:1 capacity:3 ptr:72DECA101060
2: length:0 capacity:0 ptr:72DECA101060
3: length:1 capacity:3 ptr:72DECA1010A0
------------------------
```