An attempted implementation of a trait method has the wrong number of function parameters.
Erroneous code example:
trait Foo {
fn foo(&self, x: u8) -> bool;
}
struct Bar;
// error: method `foo` has 1 parameter but the declaration in trait `Foo::foo`
// has 2
impl Foo for Bar {
fn foo(&self) -> bool { true }
}For example, the Foo trait has a method foo with two function parameters
(&self and u8), but the implementation of foo for the type Bar omits
the u8 parameter. To fix this error, they must have the same parameters:
trait Foo {
fn foo(&self, x: u8) -> bool;
}
struct Bar;
impl Foo for Bar {
fn foo(&self, x: u8) -> bool { // ok!
true
}
}