Struct SafeInteger 

pub struct SafeInteger<T: SafeIntegerPrimitive>(/* private fields */);

A u64 or i64 that crosses the JS boundary as a number instead of a BigInt.

Many JS APIs type integer counts as number. A plain u64 in a binding signature is a BigInt at the boundary, so SafeInteger<u64> is used instead to keep the Rust integer type while passing a number. In TypeScript it is number.

use wasm_bindgen::SafeInteger;

#[wasm_bindgen]
extern "C" {
    type QueueMetrics;
    #[wasm_bindgen(method, getter, js_name = backlogCount)]
    fn backlog_count(this: &QueueMetrics) -> SafeInteger<u64>;
}

let count = metrics.backlog_count();
if count > 10_000 { /* ... */ }
let next: u64 = (count + 1).into();

It derefs to the inner integer, so its methods are available directly, and compares and does arithmetic with both itself and the inner type.

The value is expected to be within ±(2^53 - 1) (Number.MAX_SAFE_INTEGER) and, for u64, non-negative, so that it is exactly representable as a JS number. Like the overflow checks on Rust’s own integers, this is only checked with debug assertions enabled: constructing a value out of range, arithmetic leaving the range, or receiving a non-integer or out-of-range number from JS then panics. Without debug assertions an out-of-range value converts lossily, as an as cast would. SafeInteger::new and the TryFrom<JsValue> conversion always check.

SafeInteger is supported in every position its conversion is reached through: arguments and returns, catch results, Option, Vec and Box<[_]>, borrowed slices passed into Rust, closure arguments, async import results and generic positions on experimental_generic_mono imports. A borrowed slice &[SafeInteger<_>] cannot be passed out to JS, since the elements have to be converted; pass a Vec or Box<[_]> instead.

Implementations

impl<T: SafeIntegerPrimitive> SafeInteger<T>

pub const MAX: Self

The largest safe integer, 2^53 - 1 (Number.MAX_SAFE_INTEGER).

pub const MIN: Self

The smallest safe integer: 0 for u64, -(2^53 - 1) (Number.MIN_SAFE_INTEGER) for i64.

pub fn new(value: T) -> Option<Self>

Wraps value, returning None if it is out of the safe integer range.

Trait Implementations

impl<T: SafeIntegerPrimitive + Add<Output = T>> Add for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Self

Performs the + operation.

impl<T: SafeIntegerPrimitive + Add<Output = T>> Add<T> for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the + operator.

fn add(self, rhs: T) -> Self

Performs the + operation.

impl<T: SafeIntegerPrimitive + Add<Output = T>> AddAssign for SafeInteger<T>

fn add_assign(&mut self, rhs: Self)

Performs the += operation.

impl<T: SafeIntegerPrimitive + Add<Output = T>> AddAssign<T> for SafeInteger<T>

fn add_assign(&mut self, rhs: T)

Performs the += operation.

impl<T: Clone + SafeIntegerPrimitive> Clone for SafeInteger<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Copy + SafeIntegerPrimitive> Copy for SafeInteger<T>

impl<T: SafeIntegerPrimitive + Debug> Debug for SafeInteger<T>

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

Formats the value using the given formatter.

impl<T: Default + SafeIntegerPrimitive> Default for SafeInteger<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: SafeIntegerPrimitive> Deref for SafeInteger<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: SafeIntegerPrimitive + Display> Display for SafeInteger<T>

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

Formats the value using the given formatter.

impl<T: SafeIntegerPrimitive + Div<Output = T>> Div for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the / operator.

fn div(self, rhs: Self) -> Self

Performs the / operation.

impl<T: SafeIntegerPrimitive + Div<Output = T>> Div<T> for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the / operator.

fn div(self, rhs: T) -> Self

Performs the / operation.

impl<T: SafeIntegerPrimitive + Div<Output = T>> DivAssign for SafeInteger<T>

fn div_assign(&mut self, rhs: Self)

Performs the /= operation.

impl<T: SafeIntegerPrimitive + Div<Output = T>> DivAssign<T> for SafeInteger<T>

fn div_assign(&mut self, rhs: T)

Performs the /= operation.

impl<T: Eq + SafeIntegerPrimitive> Eq for SafeInteger<T>

impl<T: SafeIntegerPrimitive> ErasableGeneric for SafeInteger<T>

type Repr = SafeInteger<T>

The singular concrete type that all generic variants can be transmuted on.

impl<T: SafeIntegerPrimitive> From<SafeInteger<T>> for JsValue

fn from(n: SafeInteger<T>) -> JsValue

Converts to this type from the input type.

impl From<SafeInteger<i64>> for i64

fn from(value: SafeInteger<i64>) -> i64

Converts to this type from the input type.

impl From<SafeInteger<u64>> for u64

fn from(value: SafeInteger<u64>) -> u64

Converts to this type from the input type.

impl<T: SafeIntegerPrimitive> From<T> for SafeInteger<T>

fn from(value: T) -> Self

Converts to this type from the input type.

impl<T: SafeIntegerPrimitive> FromWasmAbi for SafeInteger<T>

type Abi = f64

The Wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: f64) -> Self

Recover a Self from Self::Abi.

impl<T: Hash + SafeIntegerPrimitive> Hash for SafeInteger<T>

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<T: SafeIntegerPrimitive> IntoWasmAbi for SafeInteger<T>

type Abi = f64

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> f64

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<T: SafeIntegerPrimitive> IntoWasmAbi for &SafeInteger<T>

type Abi = f64

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> f64

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<T: SafeIntegerPrimitive> MaybeFromWasmAbi for SafeInteger<T>

type MaybeAbi = <f64 as MaybeFromWasmAbi>::MaybeAbi

The ABI of Option<Self>.

unsafe fn from_maybe_abi(js: Self::MaybeAbi) -> Self

Recovers a value from the Option<Self> ABI, once is_none has ruled None out.

fn is_none(js: &Self::MaybeAbi) -> bool

Tests the ABI value for None.

impl<T: SafeIntegerPrimitive> MaybeIntoWasmAbi for SafeInteger<T>

type MaybeAbi = <f64 as MaybeIntoWasmAbi>::MaybeAbi

The ABI of Option<Self>.

fn into_maybe_abi(self) -> Self::MaybeAbi

Converts a value into the Option<Self> ABI.

fn none() -> Self::MaybeAbi

Returns the ABI value for None, which JS reads as undefined.

impl<T: SafeIntegerPrimitive> MaybeIntoWasmAbi for &SafeInteger<T>

type MaybeAbi = <f64 as MaybeIntoWasmAbi>::MaybeAbi

The ABI of Option<Self>.

fn into_maybe_abi(self) -> Self::MaybeAbi

Converts a value into the Option<Self> ABI.

fn none() -> Self::MaybeAbi

Returns the ABI value for None, which JS reads as undefined.

impl<T: SafeIntegerPrimitive + Mul<Output = T>> Mul for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the * operator.

fn mul(self, rhs: Self) -> Self

Performs the * operation.

impl<T: SafeIntegerPrimitive + Mul<Output = T>> Mul<T> for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the * operator.

fn mul(self, rhs: T) -> Self

Performs the * operation.

impl<T: SafeIntegerPrimitive + Mul<Output = T>> MulAssign for SafeInteger<T>

fn mul_assign(&mut self, rhs: Self)

Performs the *= operation.

impl<T: SafeIntegerPrimitive + Mul<Output = T>> MulAssign<T> for SafeInteger<T>

fn mul_assign(&mut self, rhs: T)

Performs the *= operation.

impl Neg for SafeInteger<i64>

type Output = SafeInteger<i64>

The resulting type after applying the - operator.

fn neg(self) -> Self

Performs the unary - operation.

impl<T: SafeIntegerPrimitive> NullableFromWasmAbi for SafeInteger<T>

fn is_null(js: &Self::MaybeAbi) -> bool

Tests the ABI value for Nullable::Null.

impl<T: SafeIntegerPrimitive> NullableIntoWasmAbi for SafeInteger<T>

fn null() -> Self::MaybeAbi

Returns the ABI value for Nullable::Null, which JS reads as null.

impl<T: SafeIntegerPrimitive> NullableIntoWasmAbi for &SafeInteger<T>

fn null() -> Self::MaybeAbi

Returns the ABI value for Nullable::Null, which JS reads as null.

impl<T: Ord + SafeIntegerPrimitive> Ord for SafeInteger<T>

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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl<T: PartialEq + SafeIntegerPrimitive> PartialEq for SafeInteger<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T: SafeIntegerPrimitive> PartialEq<SafeInteger<T>> for JsValue

fn eq(&self, other: &SafeInteger<T>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl PartialEq<SafeInteger<i64>> for i64

fn eq(&self, other: &SafeInteger<i64>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl PartialEq<SafeInteger<u64>> for u64

fn eq(&self, other: &SafeInteger<u64>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<T: SafeIntegerPrimitive> PartialEq<T> for SafeInteger<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T: PartialOrd + SafeIntegerPrimitive> PartialOrd for SafeInteger<T>

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.

impl PartialOrd<SafeInteger<i64>> for i64

fn partial_cmp(&self, other: &SafeInteger<i64>) -> 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.

impl PartialOrd<SafeInteger<u64>> for u64

fn partial_cmp(&self, other: &SafeInteger<u64>) -> 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.

impl<T: SafeIntegerPrimitive> PartialOrd<T> for SafeInteger<T>

fn partial_cmp(&self, other: &T) -> 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.

impl<T: SafeIntegerPrimitive> Promising for SafeInteger<T>

type Resolution = SafeInteger<T>

The type that this value resolves to.

impl<T: SafeIntegerPrimitive + Rem<Output = T>> Rem for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the % operator.

fn rem(self, rhs: Self) -> Self

Performs the % operation.

impl<T: SafeIntegerPrimitive + Rem<Output = T>> Rem<T> for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the % operator.

fn rem(self, rhs: T) -> Self

Performs the % operation.

impl<T: SafeIntegerPrimitive + Rem<Output = T>> RemAssign for SafeInteger<T>

fn rem_assign(&mut self, rhs: Self)

Performs the %= operation.

impl<T: SafeIntegerPrimitive + Rem<Output = T>> RemAssign<T> for SafeInteger<T>

fn rem_assign(&mut self, rhs: T)

Performs the %= operation.

impl<T: PartialEq + SafeIntegerPrimitive> StructuralPartialEq for SafeInteger<T>

impl<T: SafeIntegerPrimitive + Sub<Output = T>> Sub for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Self

Performs the - operation.

impl<T: SafeIntegerPrimitive + Sub<Output = T>> Sub<T> for SafeInteger<T>

type Output = SafeInteger<T>

The resulting type after applying the - operator.

fn sub(self, rhs: T) -> Self

Performs the - operation.

impl<T: SafeIntegerPrimitive + Sub<Output = T>> SubAssign for SafeInteger<T>

fn sub_assign(&mut self, rhs: Self)

Performs the -= operation.

impl<T: SafeIntegerPrimitive + Sub<Output = T>> SubAssign<T> for SafeInteger<T>

fn sub_assign(&mut self, rhs: T)

Performs the -= operation.

impl<T: SafeIntegerPrimitive> TryFrom<&JsValue> for SafeInteger<T>

type Error = JsValue

The type returned in the event of a conversion error.

fn try_from(value: &JsValue) -> Result<Self, JsValue>

Performs the conversion.

impl<T: SafeIntegerPrimitive> TryFrom<JsValue> for SafeInteger<T>

type Error = JsValue

The type returned in the event of a conversion error.

fn try_from(value: JsValue) -> Result<Self, JsValue>

Performs the conversion.

impl<T: SafeIntegerPrimitive> TryFromJsValue for SafeInteger<T>

fn try_from_js_value_ref(value: &JsValue) -> Option<Self>

Performs the conversion.

const NULLABLE: bool = false

Whether Self accepts null as a distinct value space, as Nullable<T> does. An enclosing Option then passes null through instead of reading it as None, so Option<T> is itself nullable exactly when T is not. JsValue does not set this: it accepts null as one value among all of them, not as a distinct space, and Option<JsValue> reads it as None like the ABI does. This is the JS-value side of NullableFromWasmAbi, which claims null at the ABI.

fn try_from_js_value(value: JsValue) -> Result<Self, JsValue>

Performs the conversion.

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for SafeInteger<T>

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for f64

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for JsOption<f64>

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for JsNullable<f64>

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for JsValue

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for JsOption<JsValue>

impl<T: SafeIntegerPrimitive> UpcastFrom<SafeInteger<T>> for JsNullable<JsValue>

impl<T: SafeIntegerPrimitive, Target: UpcastFrom<SafeInteger<T>>> UpcastFrom<SafeInteger<T>> for Option<Target>

impl<T: SafeIntegerPrimitive, Target: UpcastFrom<SafeInteger<T>>> UpcastFrom<SafeInteger<T>> for Nullable<Target>

impl<T: SafeIntegerPrimitive> VectorFromWasmAbi for SafeInteger<T>

type Abi = WasmSlice

unsafe fn vector_from_abi(js: WasmSlice) -> Box<[Self]>

impl<T: SafeIntegerPrimitive> VectorIntoWasmAbi for SafeInteger<T>

type Abi = WasmSlice

fn vector_into_abi(vector: Box<[Self]>) -> WasmSlice