# Struct cargo::core::resolver::RemainingCandidates

source ·

    struct RemainingCandidates {
        remaining: RcVecIter<Summary>,
        has_another: Option<Summary>,
    }

Expand description

A helper “iterator” used to extract candidates within a current `Context` of a dependency graph.

This struct doesn’t literally implement the `Iterator` trait (requires a few more inputs) but in general acts like one. Each `RemainingCandidates` is created with a list of candidates to choose from. When attempting to iterate over the list of candidates only valid candidates are returned. Validity is defined within a `Context`.

Candidates passed to `new` may not be returned from `next` as they could be filtered out, and as they are filtered the causes will be added to `conflicting_prev_active`.

## Fields§

§`remaining: RcVecIter<Summary>`§`has_another: Option<Summary>`

## Implementations§

source§

### impl RemainingCandidates

source

#### fn new(candidates: &Rc<Vec<Summary>>) -> RemainingCandidates

source

#### fn next( &mut self, conflicting_prev_active: &mut BTreeMap<PackageId, ConflictReason>, cx: &Context, dep: &Dependency, parent: PackageId ) -> Option<(Summary, bool)>

Attempts to find another candidate to check from this list.

This method will attempt to move this iterator forward, returning a candidate that’s possible to activate. The `cx` argument is the current context which determines validity for candidates returned, and the `dep` is the dependency listing that we’re activating for.

If successful a `(Candidate, bool)` pair will be returned. The `Candidate` is the candidate to attempt to activate, and the `bool` is an indicator of whether there are remaining candidates to try of if we’ve reached the end of iteration.

If we’ve reached the end of the iterator here then `Err` will be returned. The error will contain a map of package ID to conflict reason, where each package ID caused a candidate to be filtered out from the original list for the reason listed.

## Trait Implementations§

source§

### impl Clone for RemainingCandidates

source§

#### fn clone(&self) -> RemainingCandidates

Returns a copy of the value. Read more
1.0.0 · source§

#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more

## Auto Trait Implementations§

§

### impl RefUnwindSafe for RemainingCandidates

§

### impl !Send for RemainingCandidates

§

### impl !Sync for RemainingCandidates

§

### impl Unpin for RemainingCandidates

§

### impl UnwindSafe for RemainingCandidates

## Blanket Implementations§

source§

### impl<T> Any for Twhere T: 'static + ?Sized,

source§

#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
source§

### impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

### impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

### impl<T> From<T> for T

const: unstable · source§

#### fn from(t: T) -> T

Returns the argument unchanged.

source§

### impl<T, U> Into<U> for Twhere U: From<T>,

const: unstable · source§

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

source§

### impl<T> Same<T> for T

§

#### type Output = T

Should always be `Self`
source§

### impl<T> ToOwned for Twhere T: Clone,

§

#### type Owned = T

The resulting type after obtaining ownership.
source§

#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

### impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

#### type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
§

### impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

§

#### fn vzip(self) -> V

## Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain `repr(...)` attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes