On Sunday, 27 November 2011 at 19:50:24 UTC, deadalnix wrote:
Hi,
I wonder why struct can't have a default constructor. TDPL
state that it is required to allow every types to have a
constant .init .
That is true, however not suffiscient. A struct can has a
void[constant] as a member and this doesn't have a .init . So
this limitation does not ensure that the benefit claimed is
garanteed.
Additionnaly, if it is the only benefit, this is pretty thin
compared to the drawback of not having a default constructor.
Think the argument is that declaring `T t;` must be CTFE, which
kind of implies a T.init state (which may have non-deterministic
values in the presence of " = void").
This is mostly for declaring things static, and the whole
"constructors are run after the .init blit".
But even then:
T t; //value is T.init, if not @disable this()
T t = T(); //Potentially run-time
I've started threads and tried to start discussions about this
before, but to no avail. It's a relativelly recurrent complain,
especially from "newer" C++ users. The older D users have either
of thrown in the towel, or implemented "workarounds".
