typedef alternative

[sybrandy]

I can't recall if you can do this with structs, but if you use classes, 
you should be able to define a "Date Part" class that has all of the 
methods and data you want.  Then, you just derive three sub-classes.

For example (and I hope the syntax is right):

class DatePart
{
    this(int f)
    {
       _foo = f;
    }

    int asNumber() { return _foo; }

    immutable int _foo;
}

class Year: DatePart {}

class Month: DatePart {}

class Day: DatePart {}

Casey

On 08/14/2010 08:47 PM, Yao G. wrote:
> Hello.
>
> Is there an alternative to typedef? I need to define three structs that
> have exactly the same methods and properties, yet represent different
> stuff.
>
> Example:
> ---
> struct Foo
> {
> this( int f ) {
> _foo = f;
> }
>
> int asNumber() {
> return _foo;
> }
>
> private immutable int _foo;
> }
>
> // This should be typedef, but as it's going to be deprecated...
> alias Foo Year;
> alias Foo Month;
> alias Foo Day;
>
>
> void bar( Year y, Month m, Day d ) {
> // ...
> }
>
> // This should compile, obviously.
> bar( Year(2010), Month(8), Day(14) );
>
> // But this shouldn't
> bar( Day(1), Year(1), Month(1) );
> ---
>
> So, what options do I have? I know that typedef is scheduled to
> deprecation, so I would like to know if there's something else.
>
>