Feature request - simpler constructors

[Steven Schveighoffer]

"kris" wrote
>
> I agree, and there more. The example given suggested
>
> # this(auto year, auto month, auto day, auto hour, auto minute, auto 
> second)
>
> in such a case, one is invariably also going to provide something like:
>
> # set (int year, int month, int day, int hour, int minute, int second)
>
> or a combination of:
>
> # date (int year, int month, int day)
> # time (int hour, int minute, int second)
>
> Hence, the ctor should actually be:
>
> # this (int year, int month, int day, int hour, int minute, int second)
> # {
> #    date (year, month, day);
> #    time (hour, minute, second);
> # }
>
> Having the compiler "fill in the gaps" here is just sloppy IMO. Do it 
> right the first time.
>

This is not always the case.  A class with immutable members comes to mind, 
such as an immutable string class.

I don't see this as any different than the C++ syntax:

Class(int x, int y)
: x(x), y(y)
{
}

But it's less typing :)

> Further, it's common practice (in D) to name local vars somewhat different 
> than the parameter names, so that DDoc has something nicer to show (recall 
> that ppl often use prefix/postfix decoration on member vars, to avoid name 
> conflict with internal functions). This 'auto' notion would simply 
> increase the level of brittleness involved. There's other reasons too, but 
> all in all I suspect this notion is borne from pure laziness rather than 
> from an engineering perspective?

I can see what you are saying, but there is always the old way of doing it 
:)  Nobody says you have to do it this way.

What I find common is creating a class that has public members, but instead 
of doing this:

class X
{
   int m1, m2, m3;
}

X x = new X;
x.m1 = 1;
x.m2 = 2;
x.m3 = 3;

I create a constructor to do that for me so I get:
X x = new X(1,2,3).

Invariably the constructor ends up looking like:

this(int m1, int m2, int m3)
{
   this.m1 = m1;
   this.m2 = m2;
   this.m3 = m3;
}

Of course, this is a simplistic example, but it does occur quite often for 
me.

-Steve