ArrayFactory SAM type / toArray

[Joshua Bloch]

Brian,

What problem are you trying solve?

    Josh

On Wed, Sep 19, 2012 at 1:39 PM, Brian Goetz <brian.goetz at oracle.com> wrote:

> In looking at the Collection API, there are two forms of toArray method,
> both of which are unfortunate:
>
>   Object[] toArray() -- returns an Object[], not a T[]
>
>   T[] toArray(T[]) -- reflective instantiation
>
> Lambdas offer us a way out of this:
>
> interface ArrayFactory<T> {
>     T[] make(int n);
> }
>
> interface Collection<T> {
>     T[] toArray(ArrayFactory<T> factory) default {
>         return toArray(factory.make(size());
>     }
> }
>
> The default is imperfect (though no worse than what clients typically do),
> and concrete implementations of Collection can do better.
>
> Given that Stream has a toArray method, my preference would be to expose
>
>   T[] toArray(ArrayFactory<T>)
>
> possibly as the only toArray method.
>
> We might be able to extend the constructor reference syntax to arrays:
> Foo[]::new.  If not, n -> new Foo[n] works fine.
>
>
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