Crate _01_places 

Crate to experiment with the API proposed in https://nadrieril.github.io/blog/2025/11/11/truly-first-class-custom-smart-pointers.html.

Modules

basic_impls 🔒

projection 🔒

place_ops 🔒

Macros

mk_field_proj

Make a unit struct that represents the projection to a particular struct field. Only works for sized types.

p

Macro that simulates the proposed new syntax. Derefs must be explicit and the identifiers used for field projections must actually be values of some Projection type, e.g. built with mk_field_proj.

Structs

NoopProj

SizedProj

Sized projection that holds only an offset.

ComposeProj

Projection P followed by Q. P may be unsized.

Enums

BorrowKind

Traits

Projection

ProjectionExt

HasPlace

PlaceBorrow

Borrow a subplace.

PlaceRead

Read a value from a subplace.

PlaceWrite

Write to a subplace.

PlaceMove

Allows moving a value out of a subplace. This uses PlaceRead::read to read the value.

PlaceDeref

Allows dereferencing a subplace that contains a pointer. The returned pointer will only be used for further place operations.

PlaceDrop

Drop the contents of a subplace.

DropHusk

Clean up a pointer whose contained place has been moved out of/dropped.

PlaceCoerce

If at a coercion site an expression e has type T but type U was expected, and T: HasPlace and T::Target: PlaceCoerce<T>, then we replace e with @T::Target::Output **e and repeat this until types match and raise an error otherwise.

PlaceWrap

If X: PlaceWrap and X::Target has a field field, then X itself acquires a virtual field named field as well. That field has type <X as PlaceWrap<proj_ty!(X::Target.field)>>::WrappedProj::Target, and WrappedProj is the projection used when we refer to that field.