error: `~const` can only be applied to `#[const_trait]` traits --> $DIR/normalize-tait-in-const.rs:25:42 | LL | const fn with_positive Fn(&'a Alias<'a>) + ~const Destruct>(fun: F) { | ^^^^^^^^^^^^^^^^^ error[E0015]: cannot call non-const closure in constant functions --> $DIR/normalize-tait-in-const.rs:26:5 | LL | fun(filter_positive()); | ^^^^^^^^^^^^^^^^^^^^^^ | = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants help: consider further restricting this bound | LL | const fn with_positive Fn(&'a Alias<'a>) + ~const Destruct + ~const std::ops::Fn<(&Alias<'_>,)>>(fun: F) { | ++++++++++++++++++++++++++++++++++++ help: add `#![feature(effects)]` to the crate attributes to enable | LL + #![feature(effects)] | error[E0493]: destructor of `F` cannot be evaluated at compile-time --> $DIR/normalize-tait-in-const.rs:25:79 | LL | const fn with_positive Fn(&'a Alias<'a>) + ~const Destruct>(fun: F) { | ^^^ the destructor for this type cannot be evaluated in constant functions LL | fun(filter_positive()); LL | } | - value is dropped here error: aborting due to 3 previous errors Some errors have detailed explanations: E0015, E0493. For more information about an error, try `rustc --explain E0015`.