On 2011-05-30 06:42, Johann MacDonagh wrote:
> I'm wondering if there's a cleaner way to do this:
>
> class Test(T = uint)
> {
> this(string s)
> {
> }
> }
>
> void main(string[] argv)
> {
> auto a = new Test!()("test");
> }
>
> I'd *like* to be able to do this:
>
> auto a = new Test("test");
>
> and:
>
> auto a = new Test!double("test");
>
> The only possibility I see is to do this:
>
> alias Test!() Test2;
>
> But that introduces two types a user has to decide between. Any ideas?
> Am I out of luck here?
The alternative is to create a helper function outside of the class which
calls the constructor. Unlike the class/struct, the function is able to use
type inference, and so you can skip the !() part. For instance, that's what
std.container.redBackTree does for RedBlackTree. In the case where you want a
default argument, the function will use the default argument or you can give
it the type directly. But you can't do that with a class/struct, because you
don't get any type inference when instantiating a class/struct.
- Jonathan M Davis
