Trait variadics::EitherRefVariadic

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pub trait EitherRefVariadic: VariadicExt + Sealed {
    type UnRefVar: VariadicExt;
    type RefVar: RefVariadic<UnRefVar = Self::UnRefVar, RefVar = Self::RefVar>;
    type MutVar: MutVariadic<UnRefVar = Self::UnRefVar, MutVar = Self::MutVar>;

    // Required methods
    fn mut_to_ref(self) -> Self::RefVar;
    fn unref_ref(&self) -> <Self::UnRefVar as VariadicExt>::AsRefVar<'_>;
}

Expand description

A variadic of either shared references, exclusive references, or both.

Provides the Self::UnRefVar associated type which is the original variadic of owned values.

This is a sealed trait.

Required Associated Types§

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type UnRefVar: VariadicExt

The un-referenced variadic. Each item will have one layer of shared references removed.

The inverse of VariadicExt::AsRefVar and VariadicExt::AsMutVar.

let un_ref: <var_type!(&u32, &String, &bool) as EitherRefVariadic>::UnRefVar =
    var_expr!(1_u32, "Hello".to_owned(), false);

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type RefVar: RefVariadic<UnRefVar = Self::UnRefVar, RefVar = Self::RefVar>

This type with all exclusive &mut references replaced with shared & references.

Returned by Self::mut_to_ref.

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type MutVar: MutVariadic<UnRefVar = Self::UnRefVar, MutVar = Self::MutVar>

This type with all shared & references replaced with exclusive references &mut.

Conversion from & to &mut is generally invalid, so a ref_to_mut() method does not exist.

Required Methods§

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fn mut_to_ref(self) -> Self::RefVar

Convert all exclusive (mut) references into shared references: RefVariadic.

let mut original = var_expr!(1_u32, "Hello".to_owned(), false);
let as_mut: var_type!(&mut u32, &mut String, &mut bool) = original.as_mut_var();
let as_ref_1: var_type!(&u32, &String, &bool) = as_mut.mut_to_ref();
let as_ref_2: var_type!(&u32, &String, &bool) = as_ref_1; // Can copy the reference version.
drop((as_ref_1, as_ref_2));