Enum rustc_trait_selection::infer::region_constraints::Constraint

source · 
pub enum Constraint<'tcx> {
    VarSubVar(RegionVid, RegionVid),
    RegSubVar(Region<'tcx>, RegionVid),
    VarSubReg(RegionVid, Region<'tcx>),
    RegSubReg(Region<'tcx>, Region<'tcx>),
}
Expand description

Represents a constraint that influences the inference process.

Variants§

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VarSubVar(RegionVid, RegionVid)

A region variable is a subregion of another.

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RegSubVar(Region<'tcx>, RegionVid)

A concrete region is a subregion of region variable.

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VarSubReg(RegionVid, Region<'tcx>)

A region variable is a subregion of a concrete region. This does not directly affect inference, but instead is checked after inference is complete.

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RegSubReg(Region<'tcx>, Region<'tcx>)

A constraint where neither side is a variable. This does not directly affect inference, but instead is checked after inference is complete.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.

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: 24 bytes

Size for each variant:

  • VarSubVar: 8 bytes
  • RegSubVar: 12 bytes
  • VarSubReg: 12 bytes
  • RegSubReg: 20 bytes