# Trait num_traits::identities::Zero [−] [src]

    pub trait Zero: Sized + Add<Self, Output = Self> {
        fn zero() -> Self;
        fn is_zero(&self) -> bool;
    }

Defines an additive identity element for `Self`.

## Required Methods

### `fn zero() -> Self`

Returns the additive identity element of `Self`, `0`.

# Laws

    a + 0 = a       ∀ a ∈ Self
    0 + a = a       ∀ a ∈ Self

# Purity

This function should return the same result at all times regardless of external mutable state, for example values stored in TLS or in `static mut`s.

### `fn is_zero(&self) -> bool`

Returns `true` if `self` is equal to the additive identity.

## Implementors

- `impl Zero for usize`
- `impl Zero for u8`
- `impl Zero for u16`
- `impl Zero for u32`
- `impl Zero for u64`
- `impl Zero for isize`
- `impl Zero for i8`
- `impl Zero for i16`
- `impl Zero for i32`
- `impl Zero for i64`
- `impl Zero for f32`
- `impl Zero for f64`
- `impl<T: Zero> Zero for Wrapping<T> where
  Wrapping<T>: Add<Output = Wrapping<T>>,`

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result
+
  Collapse/expand all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)