Struct rustc_mir_build::thir::pattern::usefulness::PatStack

struct PatStack<'p, 'tcx> {
    pats: SmallVec<[&'p Pat<'tcx>; 2]>,
    head_ctor: OnceCell<Constructor<'tcx>>,
}

A row of a matrix. Rows of len 1 are very common, which is why SmallVec[_; 2] works well.

Fields

pats: SmallVec<[&'p Pat<'tcx>; 2]>

head_ctor: OnceCell<Constructor<'tcx>>

Cache for the constructor of the head

Implementations

impl<'p, 'tcx> PatStack<'p, 'tcx>

fn from_pattern(pat: &'p Pat<'tcx>) -> Self

fn from_vec(vec: SmallVec<[&'p Pat<'tcx>; 2]>) -> Self

fn is_empty(&self) -> bool

fn len(&self) -> usize

fn head(&self) -> &'p Pat<'tcx>

fn head_ctor<'a>(
    &'a self,
    cx: &MatchCheckCtxt<'p, 'tcx>
) -> &'a Constructor<'tcx>

fn iter(&self) -> impl Iterator<Item = &Pat<'tcx>>

fn expand_or_pat<'a>(
    &'a self
) -> impl Iterator<Item = PatStack<'p, 'tcx>> + Captures<'a>

fn pop_head_constructor(
    &self,
    ctor_wild_subpatterns: &Fields<'p, 'tcx>
) -> PatStack<'p, 'tcx>

This computes S(self.head_ctor(), self). See top of the file for explanations.

Structure patterns with a partial wild pattern (Foo { a: 42, .. }) have their missing fields filled with wild patterns.

This is roughly the inverse of Constructor::apply.

Trait Implementations

impl<'p, 'tcx> Clone for PatStack<'p, 'tcx>

fn clone(&self) -> PatStack<'p, 'tcx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'p, 'tcx> Debug for PatStack<'p, 'tcx>

Pretty-printing for matrix row.

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

Formats the value using the given formatter.

impl<'p, 'tcx> Default for PatStack<'p, 'tcx>

fn default() -> Self

Returns the “default value” for a type.

impl<'p, 'tcx> FromIterator<&'p Pat<'tcx>> for PatStack<'p, 'tcx>

fn from_iter<T>(iter: T) -> Self where
    T: IntoIterator<Item = &'p Pat<'tcx>>, 

Creates a value from an iterator.

impl<'p, 'tcx> FromIterator<PatStack<'p, 'tcx>> for Matrix<'p, 'tcx>

fn from_iter<T>(iter: T) -> Self where
    T: IntoIterator<Item = PatStack<'p, 'tcx>>, 

Creates a value from an iterator.

impl<'p, 'tcx> PartialEq<PatStack<'p, 'tcx>> for PatStack<'p, 'tcx>

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

Layout

Note: Most layout information is completely unstable and may be different between compiler versions and platforms. 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: 72 bytes