On 03/28/14 20:00, H. S. Teoh wrote:
> Today I ran into an interesting situation where I have a function f that
> needs to return ranges of different types (but identical element types):
>
> auto f(A...)(A args) {
> ...
> if (someCondition)
> return cartesianProduct(x, y)
> .joiner;
> else
> return cartesianProduct(x, y)
> .joiner
> .filter!someFilter;
> }
>
> This obviously can't compile, because the return types are not the same.
> (Note that someCondition is only known at runtime.) But abstractly
> speaking, it *should* work, because the element type of the returned
> range is identical.
>
> So how would I implement something like this?
eg
auto f(A...)(A args) {
...
return cartesianProduct(x, y)
.joiner
.filter!(a=>somecondition?true:somefilter(a));
}
artur
