|  | error[E0658]: cannot call conditionally-const associated function `<Vec<usize> as Default>::default` in constant functions | 
|  | --> $DIR/std-impl-gate.rs:13:5 | 
|  | | | 
|  | LL |     Default::default() | 
|  | |     ^^^^^^^^^^^^^^^^^^ | 
|  | | | 
|  | = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants | 
|  | = note: see issue #143874 <https://github.com/rust-lang/rust/issues/143874> for more information | 
|  | = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable | 
|  | = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date | 
|  |  | 
|  | error: `Default` is not yet stable as a const trait | 
|  | --> $DIR/std-impl-gate.rs:13:5 | 
|  | | | 
|  | LL |     Default::default() | 
|  | |     ^^^^^^^^^^^^^^^^^^ | 
|  | | | 
|  | help: add `#![feature(const_default)]` to the crate attributes to enable | 
|  | | | 
|  | LL + #![feature(const_default)] | 
|  | | | 
|  |  | 
|  | error: aborting due to 2 previous errors | 
|  |  | 
|  | For more information about this error, try `rustc --explain E0658`. |