Trait TList

pub trait TList: Sealed + TListImpl {
    type Concat<Rhs: TList>: TList;
    type Reverse: TList;
    type IsEmpty: Bit;
    type Len: UnsignedExt;

    const IS_EMPTY: bool;
    const LEN: usize;
}

Type-level lists.

This trait is a “type-level enum”. TList, TNil and TCons are the type-level equivalent of the following value-level enum:

pub enum List<H, T> {
  Nil,
  Cons(H, T),
}

This trait can be considered a ‘marker’ trait: It has no methods to be called at runtime. It only has some GATs.

Rather than calling these GATs directly, it is recommended to instead use their type aliases, as calling those is less verbose:

use tlist::*;

// This is possible...
type Fine = <TList![u8, u16] as TList>::Concat<TList![u32, u64]>;

// But this is more readable:
type Nice = Concat<TList![u8, u16], TList![u32, u64]>;

static_assertions::assert_type_eq_all!(Fine, Nice);

Required Associated Constants

const IS_EMPTY: bool

True iff the list is empty, false otherwise.

Returns a bool as associated const value. If you’d rather use a type, see IsEmpty (which needs typenum feature to be enabled)

Also see the Empty and NonEmpty traits.

const LEN: usize

The amount of elements in the list.

Returns an usize as associated const value. If you’d rather use a type, see Len (which needs typenum feature to be enabled)

Required Associated Types

type Concat<Rhs: TList>: TList

Implementation of Concat.

type Reverse: TList

Implementation of Reverse.

type IsEmpty: Bit

Available on crate feature typenum only.

Implementation of IsEmpty.

type Len: UnsignedExt

Available on crate feature typenum only.

Implementation of Len.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl TList for TNil

const IS_EMPTY: bool = true

const LEN: usize = 0usize

type Concat<Rhs: TList> = Rhs

type Reverse = TNil

type IsEmpty = B1

type Len = UTerm

impl<H, T: TList> TList for TCons<H, T>

const IS_EMPTY: bool = false

const LEN: usize

type Concat<Rhs: TList> = TCons<H, <T as TList>::Concat<Rhs>>

type Reverse = <<T as TList>::Reverse as TList>::Concat<TCons<H, TNil>>

type IsEmpty = B0

type Len = <<T as TList>::Len as UnsignedExt>::Succ