Trait DictionaryKey

pub unsafe trait DictionaryKey:
    NativeType
    + TryInto<usize>
    + TryFrom<usize>
    + Hash {
    const KEY_TYPE: IntegerType;
    const MAX_USIZE_VALUE: usize;

    // Provided methods
    unsafe fn as_usize(self) -> usize { ... }
    unsafe fn from_usize_unchecked(x: usize) -> Self { ... }
    fn always_fits_usize() -> bool { ... }
}

Trait denoting NativeTypes that can be used as keys of a dictionary.

Safety

Any implementation of this trait must ensure that always_fits_usize only returns true if all values succeeds on value::try_into::<usize>().unwrap().

Required Associated Constants

const KEY_TYPE: IntegerType

The corresponding IntegerType of this key

const MAX_USIZE_VALUE: usize

Provided Methods

unsafe fn as_usize(self) -> usize

Represents this key as a usize.

Safety

The caller must have checked that the value can be casted to usize.

unsafe fn from_usize_unchecked(x: usize) -> Self

Create a key from a usize without checking bounds.

Safety

The caller must have checked that the value can be created from a usize.

fn always_fits_usize() -> bool

If the key type always can be converted to usize.

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.

Implementations on Foreign Types

impl DictionaryKey for i8

const KEY_TYPE: IntegerType = IntegerType::Int8

const MAX_USIZE_VALUE: usize = 127usize

impl DictionaryKey for i16

const KEY_TYPE: IntegerType = IntegerType::Int16

const MAX_USIZE_VALUE: usize = 32_767usize

impl DictionaryKey for i32

const KEY_TYPE: IntegerType = IntegerType::Int32

const MAX_USIZE_VALUE: usize = 2_147_483_647usize

impl DictionaryKey for i64

const KEY_TYPE: IntegerType = IntegerType::Int64

const MAX_USIZE_VALUE: usize = 4_294_967_295usize

impl DictionaryKey for u8

const KEY_TYPE: IntegerType = IntegerType::UInt8

const MAX_USIZE_VALUE: usize = 255usize

fn always_fits_usize() -> bool

impl DictionaryKey for u16

const KEY_TYPE: IntegerType = IntegerType::UInt16

const MAX_USIZE_VALUE: usize = 65_535usize

fn always_fits_usize() -> bool

impl DictionaryKey for u32

const KEY_TYPE: IntegerType = IntegerType::UInt32

const MAX_USIZE_VALUE: usize = 4_294_967_295usize

fn always_fits_usize() -> bool

impl DictionaryKey for u64

const KEY_TYPE: IntegerType = IntegerType::UInt64

const MAX_USIZE_VALUE: usize = 4_294_967_295usize

Implementors