On Wednesday, 19 September 2012 at 12:31:08 UTC, Maxim Fomin
wrote:
On Wednesday, 19 September 2012 at 11:51:13 UTC, monarch_dodra
wrote:
The biggest issue with not having a no-arg constructor can
easilly be seen if you have ever worked with a "Reference
Semantic" semantic struct: A struct that has a pointer to a
payload. Basically, a class, but without the inherited Object
polymorphism.
This means that you still have a class object. What is design
behind inserting class into the structure for the sake of
escaping from classes?
That's not the point at all. For starters, the "Payload" is
another struct, NOT a class wrapped in a struct.
As for why we aren't using a class to begin with? First, because
a class wraps much more than we want: polymorphism, adherence to
a base "Object Type", virtual opEquals, RTTI...
But mostly, because the object we manipulate is a struct and has
always been a struct. It uses reference semantics, but is in dire
need of a an initialization to default.
On Wednesday, 19 September 2012 at 14:09:10 UTC, deadalnix wrote:
Le 19/09/2012 15:24, Timon Gehr a écrit :
I don't think making the use of optional parens affect
semantics is an
idea worth following.
I have to agree with that.
However, argument-less constructor is something required for
struct. The problem is raised on a regular basis on this
newsgroup, and some solution already have been proposed.
As discussed earlier in the reference thread, the compiler will
have to track down initialization at some point. A struct with
an argument-less constructor which isn't initialized must be an
error. This will avoid the () semantic dichotomy while solving
that problem.
Would you happen to have some links to those proposed solutions,
or reword them here for us?
