Trait core::marker::StructuralPartialEq
source · [−]pub trait StructuralPartialEq { }
Expand description
Required trait for constants used in pattern matches.
Any type that derives PartialEq
automatically implements this trait,
regardless of whether its type-parameters implement Eq
.
If a const
item contains some type that does not implement this trait,
then that type either (1.) does not implement PartialEq
(which means the
constant will not provide that comparison method, which code generation
assumes is available), or (2.) it implements its own version of
PartialEq
(which we assume does not conform to a structural-equality
comparison).
In either of the two scenarios above, we reject usage of such a constant in a pattern match.
See also the structural match RFC, and issue 63438 which motivated migrating from attribute-based design to this trait.
Implementors
impl StructuralPartialEq for core::cmp::Ordering
impl StructuralPartialEq for Alignment
impl StructuralPartialEq for FpCategory
impl StructuralPartialEq for IntErrorKind
impl StructuralPartialEq for Which
impl StructuralPartialEq for SearchStep
impl StructuralPartialEq for core::sync::atomic::Ordering
impl StructuralPartialEq for AllocError
impl StructuralPartialEq for Layout
impl StructuralPartialEq for LayoutError
impl StructuralPartialEq for TypeId
impl StructuralPartialEq for CpuidResult
Available on x86 or x86-64 only.