Struct rustc_mir_build::build::matches::BuiltMatchTree

struct BuiltMatchTree<'tcx> {
    branches: Vec<MatchTreeBranch<'tcx>>,
    otherwise_block: BasicBlock,
    fake_borrow_temps: Vec<(Place<'tcx>, Local, FakeBorrowKind)>,
}

The result of generating MIR for a pattern-matching expression. Each input branch/arm/pattern gives rise to an output MatchTreeBranch. If one of the patterns matches, we branch to the corresponding success_block. If none of the patterns matches, we branch to otherwise_block.

Each branch is made of one of more sub-branches, corresponding to or-patterns. E.g.

match foo {
    (x, false) | (false, x) => {}
    (true, true) => {}
}

Here the first arm gives the first MatchTreeBranch, which has two sub-branches, one for each alternative of the or-pattern. They are kept separate because each needs to bind x to a different place.

Fields

branches: Vec<MatchTreeBranch<'tcx>>

otherwise_block: BasicBlock

fake_borrow_temps: Vec<(Place<'tcx>, Local, FakeBorrowKind)>

If any of the branches had a guard, we collect here the places and locals to fakely borrow to ensure match guards can’t modify the values as we match them. For more details, see util::collect_fake_borrows.

Trait Implementations

impl<'tcx> Debug for BuiltMatchTree<'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: 56 bytes