# 1.0.0[−][src]Module std::convert

Traits for conversions between types.

The traits in this module provide a general way to talk about conversions from one type to another. They follow the standard Rust conventions of `as`/`into`/`from`.

Like many traits, these are often used as bounds for generic functions, to support arguments of multiple types.

- Implement the `As*` traits for reference-to-reference conversions
- Implement the `Into` trait when you want to consume the value in the conversion
- The `From` trait is the most flexible, useful for value and reference conversions
- The `TryFrom` and `TryInto` traits behave like `From` and `Into`, but allow for the conversion to fail

As a library author, you should prefer implementing `From<T>` or `TryFrom<T>` rather than `Into<U>` or `TryInto<U>`, as `From` and `TryFrom` provide greater flexibility and offer equivalent `Into` or `TryInto` implementations for free, thanks to a blanket implementation in the standard library. However, there are some cases where this is not possible, such as creating conversions into a type defined outside your library, so implementing `Into` instead of `From` is sometimes necessary.

# Generic Implementations

- `AsRef` and `AsMut` auto-dereference if the inner type is a reference
- `From``<U> for T` implies `Into``<T> for U`
- `TryFrom``<U> for T` implies `TryInto``<T> for U`
- `From` and `Into` are reflexive, which means that all types can `into` themselves and `from` themselves

See each trait for usage examples.

## Enums

Infallible | The error type for errors that can never happen.

## Traits

AsMut | A cheap, mutable reference-to-mutable reference conversion.
AsRef | A cheap reference-to-reference conversion. Used to convert a value to a reference value within generic code.
From | Simple and safe type conversions in to `Self`. It is the reciprocal of `Into`.
Into | A conversion that consumes `self`, which may or may not be expensive. The reciprocal of `From`.
TryFrom | Simple and safe type conversions that may fail in a controlled way under some circumstances. It is the reciprocal of `TryInto`.
TryInto | An attempted conversion that consumes `self`, which may or may not be expensive.

## Functions

identity | An identity function.

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