On Sunday, 16 January 2022 at 23:03:49 UTC, Ali Çehreli wrote:
That's not correct. There are many range algorithms that are
lazy to defer memory allocation but array() is not one of
those. array() does eagerly allocate memory, which is it's
whole purpose:
https://dlang.org/phobos/std_array.html#array
"Allocates an array and initializes it with copies of the
elements of range r."
So, that range expression has the same allocations as your "GC
allocation" line above.
Honestly, that is what I thought, and expected.
However, when I compiled with: -profile=gc .. it indicated no GC
allocation going on. That's really why I got confused - because,
as you say, the array statement (as I understand it)will result
in a dynamically allocated array (i.e. allocated on GC heap).
But -profile=gc .. says no. It's not.
int[][] mArr = [[1, 2], [3, 4], [5, 6], [7, 8]]; // GC allocation
occurs.
int[][] mArr = iota(1, 9).chunks(2).map!array.array; // No GC
allocation occurs.
