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.