On Saturday, 9 April 2016 at 16:44:06 UTC, ag0aep6g wrote:
On 09.04.2016 18:13, Uranuz wrote:
http://dpaste.dzfl.pl/523781df67ab
For reference, the code:
----
import std.stdio;
void main()
{
string[][string] mapka;
string[]* mapElem = "item" in mapka; //Checking if I have item
if( !mapElem )
mapElem = &( mapka["item"] = [] ); //Creating empty element
inside map
writeln( (*mapElem).capacity );
//Appending should reallocate, so pointer to array should
change
*mapElem ~= ["dog", "cat", "horse", "penguin", "fish", "frog"];
//But AA still somehow knows the right pointer
writeln(mapka);
//It works, but I dont understand why?
}
----
mapElem is not a pointer to the elements of the array. It's a
pointer to the dynamic array structure which holds the pointer
to the data and the length. That means, the reallocation
doesn't change mapElem. It changes (*mapElem).ptr.
Thanks. It's clear now. AA holds not `array struct` itself
inside, but pointer to it. So reallocation affects ptr to
allocated memory but not pointer to `array struct`. I think
that's it.
