Struct ClosureData 

pub struct ClosureData {
    pub min_captures: FxIndexMap<BindingId, Vec<CapturedPlace>>,
    pub fake_reads: Box<[(Place, FakeReadCause, SmallVec<[CaptureSourceStack; 2]>)]>,
}

Fields

min_captures: FxIndexMap<BindingId, Vec<CapturedPlace>>

Tracks the minimum captures required for a closure; see MinCaptureInformationMap for more details.

fake_reads: Box<[(Place, FakeReadCause, SmallVec<[CaptureSourceStack; 2]>)]>

Tracks the fake reads required for a closure and the reason for the fake read. When performing pattern matching for closures, there are times we don’t end up reading places that are mentioned in a closure (because of _ patterns). However, to ensure the places are initialized, we introduce fake reads. Consider these two examples:

let x: u8;
let c = || match x { _ => () };

In this example, we don’t need to actually read/borrow x in c, and so we don’t want to capture it. However, we do still want an error here, because x should have to be initialized at the point where c is created. Therefore, we add a “fake read” instead.

let c = || {
    let (t1, t2) = t;
}

In the second example, we capture the disjoint fields of t (t.0 & t.1), but we never capture t. This becomes an issue when we build MIR as we require information on t in order to create place t.0 and t.1. We can solve this issue by fake reading t.

Trait Implementations

impl Clone for ClosureData

fn clone(&self) -> ClosureData

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClosureData

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ClosureData

fn default() -> ClosureData

Returns the “default value” for a type.

impl PartialEq for ClosureData

fn eq(&self, other: &ClosureData) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ClosureData

impl StructuralPartialEq for ClosureData