Error code E0281
Note: this error code is no longer emitted by the compiler.
You tried to supply a type which doesn't implement some trait in a location
which expected that trait. This error typically occurs when working with
Fn
-based types. Erroneous code example:
fn foo<F: Fn(usize)>(x: F) { } fn main() { // type mismatch: ... implements the trait `core::ops::Fn<(String,)>`, // but the trait `core::ops::Fn<(usize,)>` is required // [E0281] foo(|y: String| { }); }
The issue in this case is that foo
is defined as accepting a Fn
with one
argument of type String
, but the closure we attempted to pass to it requires
one arguments of type usize
.