Struct rustc_middle::ty::print::pretty::RegionHighlightMode

pub struct RegionHighlightMode {
    highlight_regions: [Option<(RegionKind, usize)>; 3],
    highlight_bound_region: Option<(BoundRegionKind, usize)>,
}

The “region highlights” are used to control region printing during specific error messages. When a “region highlight” is enabled, it gives an alternate way to print specific regions. For now, we always print those regions using a number, so something like “'0”.

Regions not selected by the region highlight mode are presently unaffected.

Fields

highlight_regions: [Option<(RegionKind, usize)>; 3]

If enabled, when we see the selected region, use “'N” instead of the ordinary behavior.

highlight_bound_region: Option<(BoundRegionKind, usize)>

If enabled, when printing a “free region” that originated from the given ty::BoundRegionKind, print it as “'1”. Free regions that would ordinarily have names print as normal.

This is used when you have a signature like fn foo(x: &u32, y: &'a u32) and we want to give a name to the region of the reference x.

Implementations

impl RegionHighlightMode

pub fn maybe_highlighting_region(
    &mut self,
    region: Option<Region<'_>>,
    number: Option<usize>
)

If region and number are both Some, invokes highlighting_region.

pub fn highlighting_region(&mut self, region: Region<'_>, number: usize)

Highlights the region inference variable vid as 'N.

pub fn highlighting_region_vid(&mut self, vid: RegionVid, number: usize)

Convenience wrapper for highlighting_region.

fn region_highlighted(&self, region: Region<'_>) -> Option<usize>

Returns Some(n) with the number to use for the given region, if any.

pub fn highlighting_bound_region(&mut self, br: BoundRegionKind, number: usize)

Highlight the given bound region. We can only highlight one bound region at a time. See the field highlight_bound_region for more detailed notes.

Trait Implementations

impl Clone for RegionHighlightMode

fn clone(&self) -> RegionHighlightMode

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Default for RegionHighlightMode

fn default() -> RegionHighlightMode

Returns the “default value” for a type.

impl Copy for RegionHighlightMode