Struct TypeHash 

pub struct TypeHash { /* private fields */ }

Runtime identity of a type, stored as a hash of its full type name.

Used instead of std::any::TypeId because it can also be built for types that only exist on the script side, from their name alone (see TypeHash::raw). Comparison, ordering and hashing all use the hash only, never the name.

assert_eq!(TypeHash::of::<i32>(), TypeHash::of::<i32>());
assert_ne!(TypeHash::of::<i32>(), TypeHash::of::<f32>());

Implementations

impl TypeHash

pub const INVALID: Self

Hash that no real type maps to, used as a null value.

This is also what TypeHash::default returns.

pub unsafe fn raw(name: &str) -> Self

Builds a hash from a type name given at runtime.

Safety

The name must be the full, qualified name of the type, the same name TypeHash::of builds its hash from. A different name makes two views of one type compare as different types. Type-erased containers use that comparison to decide if a cast is safe.

pub unsafe fn raw_static(name: &'static str) -> Self

Same as TypeHash::raw, but keeps the name for diagnostics when the typehash_debug_name feature is on.

Safety

Same as TypeHash::raw.

pub fn of_runtime(qualified_name: &str) -> Self

Builds the hash of a type that exists only on the script side, from its qualified name.

The name is salted with NUL bytes, which std::any::type_name never produces. So a runtime type never gets the same hash as a Rust type, and a runtime value never passes the check that reads it as a Rust type. Reflection stays the only way to read such a value.

This is safe, unlike TypeHash::raw, because the hash it builds cannot match a Rust type.

assert_eq!(
    TypeHash::of_runtime("game::Player"),
    TypeHash::of_runtime("game::Player")
);
assert_ne!(
    TypeHash::of_runtime("game::Player"),
    TypeHash::of_runtime("game::Vector")
);
assert_ne!(TypeHash::of_runtime("i32"), TypeHash::of::<i32>());

pub fn of<T: ?Sized>() -> Self

Builds the hash of a Rust type known at compile time.

pub fn is_valid(&self) -> bool

Returns false only for TypeHash::INVALID.

pub fn hash(&self) -> u64

Returns the raw hash value.

Trait Implementations

impl Clone for TypeHash

fn clone(&self) -> TypeHash

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for TypeHash

impl Debug for TypeHash

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TypeHash

fn default() -> Self

Returns the “default value” for a type.

impl Display for TypeHash

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for TypeHash

impl Hash for TypeHash

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for TypeHash

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for TypeHash

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for TypeHash

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.