[−][src]Trait structural::field::rev_get_field::OptRevGetFieldMut

pub trait OptRevGetFieldMut<'a, This>: RevGetFieldMutImpl<'a, This, Err = FailedAccess> { }

A trait alias for a fallible RevGetFieldMutImpl, generally used to access fields inside enums.

This is the type we are accessing,and Self is a field path.

Example

This example shows how you can access an enum field by mutable reference.

use structural::field::OptRevGetFieldMut;
use structural::for_examples::{StructFoo, StructBar, Struct3};
use structural::{StructuralExt,FP,fp};

let mut struct_=Struct3{
    foo: Some(0),
    bar: "hi",
    baz: StructBar{
        bar: StructFoo{
            foo:Some("hello"),
        },
    },
};

assert_eq!( get_nested(&mut struct_), Some(&mut "hello") );

fn get_nested<'a,T>(this:&'a mut T)->Option<&'a mut &'static str>
where
    FP!(baz.bar.foo?): OptRevGetFieldMut<'a,T,Ty=&'static str>
{
    this.field_mut(fp!(baz.bar.foo?))
}

Implementors

impl<'a, Path, This> OptRevGetFieldMut<'a, This> for Path where
    Path: RevGetFieldMutImpl<'a, This, Err = FailedAccess>, [src]

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