Rust errors / Ownership and borrowing
Rust compiler error · checked with rustc 1.99.0
Rust error E0226: only a single explicit lifetime bound is permitted
What it meansMore than one explicit lifetime bound was used on a trait object.
What rustc prints
error[E0226]: only a single explicit lifetime bound is permitted
--> main.rs:3:33
|
3 | type T<'a, 'b> = dyn Foo + 'a + 'b; // error: Trait object `arg` has two
| ^^Real output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.
E0226Ownership and borrowing
Activein rustc 1.99.0
8related errors linked below
The compiler team's explanation
More than one explicit lifetime bound was used on a trait object.
Example of erroneous code:
trait Foo {}
type T<'a, 'b> = dyn Foo + 'a + 'b; // error: Trait object `arg` has two
// lifetime bound, 'a and 'b.Here T is a trait object with two explicit lifetime bounds, 'a and 'b.
Only a single explicit lifetime bound is permitted on trait objects. To fix this error, consider removing one of the lifetime bounds:
trait Foo {}
type T<'a> = dyn Foo + 'a;From rustc --explain E0226 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
Related errors
- E0382borrow of moved value
- E0499cannot borrow as mutable more than once at a time
- E0502cannot borrow as mutable because it is also borrowed as immutable
- E0106missing lifetime specifier
- E0195lifetime parameters do not match the trait definition
- E0207the type parameter `T` is not constrained by the impl trait, self type, or predicates
- E0227ambiguous lifetime bound, explicit lifetime bound required
- E0228cannot deduce the lifetime bound for this trait object type from context
Up next
Often hit nextE0382: borrow of moved valueA related error from the same family.Read it next →Did this answer your question?