Expand description
Trait for equality comparisons which are equivalence relations.
This means, that in addition to a == b and a != b being strict inverses, the equality must
be (for all a, b and c):
- reflexive:
a == a;
- symmetric:
a == b implies b == a; and
- transitive:
a == b and b == c implies a == c.
This property cannot be checked by the compiler, and therefore Eq implies
PartialEq, and has no extra methods.
This trait can be used with #[derive]. When derived, because Eq has
no extra methods, it is only informing the compiler that this is an
equivalence relation rather than a partial equivalence relation. Note that
the derive strategy requires all fields are Eq, which isn’t
always desired.
If you cannot use the derive strategy, specify that your type implements
Eq, which has no methods:
enum BookFormat { Paperback, Hardback, Ebook }
struct Book {
isbn: i32,
format: BookFormat,
}
impl PartialEq for Book {
fn eq(&self, other: &Self) -> bool {
self.isbn == other.isbn
}
}
impl Eq for Book {}
Run
sourceThis is supported on Unix only.
sourceimpl<A, B, C, D> Eq for (A, B, C, D) where
A: Eq,
B: Eq,
C: Eq,
D: Eq + ?Sized,
sourceimpl<A, B, C, D, E> Eq for (A, B, C, D, E) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F> Eq for (A, B, C, D, E, F) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G> Eq for (A, B, C, D, E, F, G) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G, H> Eq for (A, B, C, D, E, F, G, H) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G, H, I> Eq for (A, B, C, D, E, F, G, H, I) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G, H, I, J> Eq for (A, B, C, D, E, F, G, H, I, J) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G, H, I, J, K> Eq for (A, B, C, D, E, F, G, H, I, J, K) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq,
K: Eq + ?Sized,
sourceimpl<A, B, C, D, E, F, G, H, I, J, K, L> Eq for (A, B, C, D, E, F, G, H, I, J, K, L) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq,
K: Eq,
L: Eq + ?Sized,
1.4.0 · sourceimpl<Ret> Eq for extern "C" fn() -> Ret
1.4.0 · sourceimpl<Ret> Eq for unsafe extern "C" fn() -> Ret
1.4.0 · sourceimpl<Ret, A> Eq for extern "C" fn(A) -> Ret
1.4.0 · sourceimpl<Ret, A> Eq for extern "C" fn(A, ...) -> Ret
1.4.0 · sourceimpl<Ret, A> Eq for unsafe fn(A) -> Ret
1.4.0 · sourceimpl<Ret, A> Eq for unsafe extern "C" fn(A) -> Ret
1.4.0 · sourceimpl<Ret, A> Eq for unsafe extern "C" fn(A, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for fn(A, B) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for extern "C" fn(A, B) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for extern "C" fn(A, B, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for unsafe fn(A, B) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for unsafe extern "C" fn(A, B) -> Ret
1.4.0 · sourceimpl<Ret, A, B> Eq for unsafe extern "C" fn(A, B, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for fn(A, B, C) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for unsafe fn(A, B, C) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for fn(A, B, C, D) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for unsafe fn(A, B, C, D) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for fn(A, B, C, D, E) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for extern "C" fn(A, B, C, D, E) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for extern "C" fn(A, B, C, D, E, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for unsafe fn(A, B, C, D, E) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for fn(A, B, C, D, E, F) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for unsafe fn(A, B, C, D, E, F) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for unsafe extern "C" fn(A, B, C, D, E, F) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F> Eq for unsafe extern "C" fn(A, B, C, D, E, F, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for fn(A, B, C, D, E, F, G) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe fn(A, B, C, D, E, F, G) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for fn(A, B, C, D, E, F, G, H) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for extern "C" fn(A, B, C, D, E, F, G, H) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe fn(A, B, C, D, E, F, G, H) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for fn(A, B, C, D, E, F, G, H, I) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe fn(A, B, C, D, E, F, G, H, I) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for fn(A, B, C, D, E, F, G, H, I, J) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
1.4.0 · sourceimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Ret