Trait frunk::labelled::LabelledGeneric

pub trait LabelledGeneric {
    type Repr;
    fn into(self) -> Self::Repr;
    fn from(repr: Self::Repr) -> Self;

    fn convert_from<Src>(src: Src) -> Self
    where
        Src: LabelledGeneric<Repr = Self::Repr>,
    { ... }
    fn sculpted_convert_from<A, Indices>(a: A) -> Self
    where
        A: LabelledGeneric,
        <A as LabelledGeneric>::Repr: Sculptor<Self::Repr, Indices>,
    { ... }
    fn transform_from<Src, Indices>(src: Src) -> Self
    where
        Src: LabelledGeneric,
        <Src as LabelledGeneric>::Repr: Sculptor<Self::Repr, Indices>,
    { ... }
}

A trait that converts from a type to a labelled generic representation.

LabelledGenerics allow us to have completely type-safe, boilerplate free conversions between different structs.

For the most part, you should be using the derivation that is available through frunk_derive to generate instances of this trait for your types.

Examples

#[macro_use] extern crate frunk;
#[macro_use] extern crate frunk_core;

#[derive(LabelledGeneric)]
struct NewUser<'a> {
    first_name: &'a str,
    last_name: &'a str,
    age: usize,
}

// Notice that the fields are mismatched in terms of ordering
#[derive(LabelledGeneric)]
struct SavedUser<'a> {
    last_name: &'a str,
    age: usize,
    first_name: &'a str,
}

let n_user = NewUser {
    first_name: "Joe",
    last_name: "Blow",
    age: 30,
};

// transform_from automagically sculpts the labelled generic
// representation of the source object to that of the target type
let s_user: SavedUser = frunk::transform_from(n_user); // done

Associated Types

type Repr

The labelled generic representation type.

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Required methods

fn into(self) -> Self::Repr

Convert a value to its representation type Repr.

fn from(repr: Self::Repr) -> Self

Convert a value's labelled representation type Repr to the values's type.

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Provided methods

fn convert_from<Src>(src: Src) -> Self where
    Src: LabelledGeneric<Repr = Self::Repr>, 

Convert from one type to another using a type with the same labelled generic representation

fn sculpted_convert_from<A, Indices>(a: A) -> Self where
    A: LabelledGeneric,
    <A as LabelledGeneric>::Repr: Sculptor<Self::Repr, Indices>, 

Deprecated:

obsolete, transform_from instead

Converts from another type A into Self assuming that A and Self have labelled generic representations that can be sculpted into each other.

Note that this method tosses away the "remainder" of the sculpted representation. In other words, anything that is not needed from A gets tossed out.

fn transform_from<Src, Indices>(src: Src) -> Self where
    Src: LabelledGeneric,
    <Src as LabelledGeneric>::Repr: Sculptor<Self::Repr, Indices>, 

Converts from another type Src into Self assuming that Src and Self have labelled generic representations that can be sculpted into each other.

Note that this method tosses away the "remainder" of the sculpted representation. In other words, anything that is not needed from Src gets tossed out.

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Implementors

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