Function rustc_middle::ty::closure::is_ancestor_or_same_capture

pub fn is_ancestor_or_same_capture(
    proj_possible_ancestor: &[ProjectionKind],
    proj_capture: &[ProjectionKind],
) -> bool

Return true if the proj_possible_ancestor represents an ancestor path to proj_capture or proj_possible_ancestor is same as proj_capture, assuming they both start off of the same root variable.

Note: It’s the caller’s responsibility to ensure that both lists of projections start off of the same root variable.

Eg: 1. foo.x which is represented using projections=[Field(x)] is an ancestor of foo.x.y which is represented using projections=[Field(x), Field(y)]. Note both foo.x and foo.x.y start off of the same root variable foo. 2. Since we only look at the projections here function will return bar.x as a valid ancestor of foo.x.y. It’s the caller’s responsibility to ensure that both projections list are being applied to the same root variable.