Taking advantage of New Rust Features #558

Ideas and tracking to take advantage of “new” features in Rust

All features to be used because of what gain they give us, not to score points. Formulate goal & gain before implementing - and write it up the pull request 🙂.

• std::alloc
• use/namespaced macros - Bump to Rust 1.30, add macros to preludes, and switch macro_use to use #517
• std::arch and target_feature
  I'd prefer significant work in this area to take place in a separate crate, that we depend on. Something that gathers low level "loops" in one place. Like this, but revived and remade
• NonZero for nonzero integers
• NonNull for pointers Change ArrayBase.ptr to NonNull type #434
• repr(transparent)
• needs_drop
• pub(crate) - This can be used for reorganization of a quite old crate structure
• const fn (1.31)
• Inclusive ranges
• Rustdoc item links
• 2018 edition path rules Update ndarray to Rust 2018 edition #567
• Run cargo fmt on repository and add format checking to CI (now that rustfmt is stable).
• Possible use of no_std + alloc. (1.36) no_std for ndarray #708
• MaybeUninit (1.36) Change uninitialized to return an array of MaybeUninit #685
• Annotations in docs to indicate when items are enabled by features. This requires the unstable doc_cfg feature, so we should probably enable this only on docs.rs. To do so, we can add this to the crate:

#![cfg_attr(docsrs, feature(doc_cfg))]

and then on each item enabled by a specific feature, we add this:

#[cfg_attr(docsrs, doc(cfg(feature = "thefeature")))]

(For an example, see async_compression.)

• Const generics Improvements using const generics #961

Future features (not relevant yet, because they don't exist in stable Rust)

• Variadic generics
• Generic associated types
• Custom DST
• Specialization
• Allocator trait
• Iterator::try_fold (Try is unstable) Forward .try_fold(), .try_rfold() on the iterators when possible #706
• trait aliases

This is a tracking issue, please edit it.