31-Jan-2013 19:21, Andrei Alexandrescu пишет:
On 1/31/13 10:18 AM, Steven Schveighoffer wrote:
On Thu, 31 Jan 2013 10:12:53 -0500, Andrei Alexandrescu
As far as I can tell classes have the same problem.
Nope.
void foo(someclass aa, int x, int y)
{
aa[x] = y;
}
void main()
{
someclass aa;
foo(aa, 1, 2); // segfault
...
}
We could easily arrange things to segfault just the same with a
struct-based implementation.
Structs are quite borked in this regard e.g. without extra efforts the
following:
somclass aa = someclass();
foor(aa, 1, 2); // segfault, surprize someclass() is someclass.init
The current workaround I find the most sensible is:
- @disable this();
- make all constructors private
- define opCall and forward it to private constructors. 0-arg versions
have to pass dummy and/or default values to get struct constructed
- automate this boilerplate until something in language is fixed? :)
The advantage is that the following is illegal:
someclass aa;
and the following works as expected:
auto aa = someclass(); //create empty container damn it!
--
Dmitry Olshansky
