On Tuesday 01 March 2011 23:52:38 Jacob Carlborg wrote:
> On 2011-03-02 08:47, Jonathan M Davis wrote:
> > On Tuesday 01 March 2011 23:43:27 Jonathan M Davis wrote:
> >> On Tuesday 01 March 2011 22:18:49 Bekenn wrote:
> >>> Code:
> >>> class MyException : Exception
> >>> {
> >>>
> >>> this(string message, string file, size_t line, Throwable next =
null)
> >>> {
> >>>
> >>> super(message, file, line, next);
> >>>
> >>> }
> >>>
> >>> this(string file = __FILE__, size_t line = __LINE__)(string
message,
> >>>
> >>> Throwable next = null)
> >>>
> >>> {
> >>>
> >>> this(message, file, line, next);
> >>>
> >>> }
> >>>
> >>> }
> >>>
> >>> void main()
> >>> {
> >>>
> >>> throw new MyException("Bluh!");
> >>>
> >>> }
> >>>
> >>> Error message:
> >>> test.d(8): Error: template test.MyException.__ctor(string file =
> >>>
> >>> __FILE__,size_t line = __LINE__) conflicts with constructor
> >>> test.MyException.this at test.d(3)
> >>>
> >>> If I remove the normal constructor and call super instead of this from
> >>>
> >>> the constructor template, then I get this slightly different error
> >>> message:
> >>> test.d(1): Error: constructor test.MyException.this conflicts with
> >>>
> >>> template test.MyException.__ctor(string file = __FILE__,uint line =
> >>> __LINE__) at test.d(3)
> >>>
> >>> Is this a compiler bug, or am I Doing It Wrong?
> >>
> >> You cannot currently templatize class constructors:
> >>
> >> http://d.puremagic.com/issues/show_bug.cgi?id=435
> >>
> >> And currently if one overload of a function is templatized, _all_
> >> overloads of that function must templatized:
> >>
> >> http://d.puremagic.com/issues/show_bug.cgi?id=2972
> >> http://d.puremagic.com/issues/show_bug.cgi?id=4749
> >
> > I should also point out that there is absolutely no need to use template
> > for what you're trying to do. Just declare the constructor like so:
> >
> > this(string message, string file = __FILE__, size_t line = __LINE__
> > Throwable next = null) { ... }
> >
> > - Jonathan M Davis
>
> I guess the reason why he would do that is to catch the file and line
> number where the constructor is called.
Except that that works with normal default arguments. I assume that he did not
realize that.
- Jonathan M Davis
