weird behave of Array?

[FeepingCreature]

On Monday, 29 July 2019 at 05:58:21 UTC, dmm wrote:
> So, d try to be smart, only make thing worse?

D is behaving exactly as it should here. You simply have a wrong 
model of what an array is in D.

In C++, an array owns its memory. In D, an array is a thin 
wrapper around GC managed memory. As such, for instance, you can 
take a reference to an array field, then resize the array, and 
the original reference will still be valid and at its original 
value.

To do what you want, use std.array.Appender, which owns its 
memory.

import std.algorithm;
import std.array;
import std.range;
import std.stdio;
void main() {
     Appender!(int[]) app;
     10.iota.each!(a => app.put(a));
     writefln!"%s, %s"(app.data.ptr, app.data);
     app.shrinkTo(0);
     10.iota.each!(a => app.put(a));
     writefln!"%s, %s"(app.data.ptr, app.data);
}