Trait HasLength 

pub trait HasLength {
    // Required method
    fn length(&self) -> usize;
}

A value with a measurable length, used by the length rules.

Implement this for your own container types to make them eligible for NonEmpty, MinLen, MaxLen, and LenRange.

Examples

use type_lib::rules::HasLength;

assert_eq!("héllo".length(), 5); // chars, not bytes
assert_eq!([1, 2, 3][..].length(), 3);

Required Methods

fn length(&self) -> usize

Returns the length of the value: chars for strings, elements otherwise.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl HasLength for str

fn length(&self) -> usize

impl HasLength for String

Available on crate feature alloc only.

fn length(&self) -> usize

impl<T> HasLength for [T]

fn length(&self) -> usize

impl<T> HasLength for Vec<T>

Available on crate feature alloc only.

fn length(&self) -> usize

impl<U: HasLength + ?Sized> HasLength for &U

fn length(&self) -> usize

Implementors