binary_search is only available for slices. Sometimes the data is not convertible to a slice, but traits could be implemented.
It would be nice to enable core features like the binary_search algorithm on the data by just implementing the required traits.
The traits for binary_search would need random access to the elements (core::ops::Index) and the length (is there a trait?)
Currently a custom binary search implementation would be required, if the data structure is not convertible to a slice.
Like mentioned below, these could be grouped like in D, into something like a SortedRange Trait.
This does not necessarily need to be part of the rust core. It could also be moved to a separate crate. Although it is nice to have reliable methods in the core libraries.