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

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: 144 bytes