Enum rustc_mir_build::build::matches::TestCase

enum TestCase<'pat, 'tcx> {
    Irrefutable {
        binding: Option<Binding<'tcx>>,
        ascription: Option<Ascription<'tcx>>,
    },
    Variant {
        adt_def: AdtDef<'tcx>,
        variant_index: VariantIdx,
    },
    Constant {
        value: Const<'tcx>,
    },
    Range(&'pat PatRange<'tcx>),
    Slice {
        len: usize,
        variable_length: bool,
    },
    Deref {
        temp: Place<'tcx>,
        mutability: Mutability,
    },
    Never,
    Or {
        pats: Box<[FlatPat<'pat, 'tcx>]>,
    },
}

Partial summary of a thir::Pat, indicating what sort of test should be performed to match/reject the pattern, and what the desired test outcome is. This avoids having to perform a full match on thir::PatKind in some places, and helps TestKind::Switch and TestKind::SwitchInt know what target values to use.

Created by MatchPairTree::for_pattern, and then inspected primarily by:

• Builder::pick_test_for_match_pair (to choose a test)
• Builder::sort_candidate (to see how the test interacts with a match pair)

Two variants are unlike the others and deserve special mention:

• Self::Irrefutable is only used temporarily when building a MatchPairTree. They are then flattened away by Builder::simplify_match_pairs, with any bindings/ascriptions incorporated into the enclosing FlatPat.
• Self::Or are not tested directly like the other variants. Instead they participate in or-pattern expansion, where they are transformed into subcandidates.
  • See Builder::expand_and_match_or_candidates.

Variants

Irrefutable

Fields

binding: Option<Binding<'tcx>>

ascription: Option<Ascription<'tcx>>

Variant

Fields

adt_def: AdtDef<'tcx>

variant_index: VariantIdx

Constant

Fields

value: Const<'tcx>

Range(&'pat PatRange<'tcx>)

Slice

Fields

len: usize

variable_length: bool

Deref

Fields

temp: Place<'tcx>

mutability: Mutability

Never

Or

Fields

pats: Box<[FlatPat<'pat, 'tcx>]>

Implementations

impl<'pat, 'tcx> TestCase<'pat, 'tcx>

fn as_range(&self) -> Option<&'pat PatRange<'tcx>>

Trait Implementations

impl<'pat, 'tcx> Clone for TestCase<'pat, 'tcx>

fn clone(&self) -> TestCase<'pat, 'tcx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'pat, 'tcx> Debug for TestCase<'pat, 'tcx>

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

Formats the value using the given formatter.

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: 88 bytes

Size for each variant:

• Irrefutable: 88 bytes
• Variant: 16 bytes
• Constant: 40 bytes
• Range: 8 bytes
• Slice: 16 bytes
• Deref: 24 bytes
• Never: 0 bytes
• Or: 16 bytes