Home

smallvec v2

original specification

the original specification was written long ago by Matt, all of which is already implemented except for the allocator API (on #387).

These are changes that weren't ready in time for 1.0 (#73).

Forward port changes from the v1 branch:

• bincode2 support Implement bincode2 encode/decode support for smallvec v1 #375

Requires newer version of Rust than current minimum (1.36):

• Use const generics to change SmallVec<[T; N]> to SmallVec<T, N>. Remove the Array trait. (RFC: rewrite based on min_const_generics for 2.0 #240, Rust 1.51).[x] Use the union representation by default and remove the optional union feature added in Use a union to reduce the size of SmallVec [v2] #94 (Rust 1.49).[x] Make SmallVec::new a const fn (Make SmallVec::new const #263).

Depends on unstable Rust features:

• Support custom allocators (Support parametric allocators #55, Allocator traits and std::heap rust-lang/rust#32838).[ ] Use specialization to optimize extend, insert_many, and from for slices of Copy types. Deprecate and remove extend_from_slice, insert_from_slice, and from_slice (Rework specialization #384, Tracking issue for specialization (RFC 1210) rust-lang/rust#31844).[x] Implement the Error trait without requiring std (Implement std::error::Error for CollectionAllocErr #355, Tracking Issue for Error in core rust-lang/rust#103765).

Breaking API changes:

• Fix variance of SmallVec<[T; N]> over T (SmallVec<[T; N]> is invariant over T #146)?[x] Remove the deprecated ExtendFromSlice trait.[x] Remove unused &self parameter from inline_size method.[x] Deprecate the write feature and add a std feature instead (Implement std::error::Error for CollectionAllocErr #355, feat: replace write feature with std feature #356).[x] Remove the non-standard insert_many method (Deprecate insert_many (and add splice?) #255)?

major changes

major changes v2 will introduce

• allocator API
• const generics type signature
• removal of unnecessary macros
• better const fn support
• specialization
• vec parity API