Rust error E0379: functions in traits cannot be declared const

What rustc prints

error[E0379]: functions in traits cannot be declared const
 --> main.rs:2:5
  |
2 |     const fn bar() -> u32; // error!
  |     ^^^^^-
  |     |
  |     functions in traits cannot be const
  |     help: remove the `const`

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.

trait Foo {
    const fn bar() -> u32; // error!
}

impl Foo for () {
    const fn bar() -> u32 { 0 } // error!
}

Related errors

• E0308mismatched types
• E0277the trait bound is not satisfied
• E0599no method named X found in the current scope
• E0433failed to resolve
• E0377the trait `CoerceUnsized` may only be implemented for a coercion between structures
• E0378the trait `DispatchFromDyn` may only be implemented for structs containing the field being coerced, ZST fields with 1 byte alignment that don't mention type/const generics, and nothing else
• E0380auto traits cannot have associated items
• E0390cannot define inherent `impl` for primitive types

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