error[E0658]: const trait impls are experimental
  --> $DIR/const_drop_is_valid.rs:6:6
   |
LL | impl const Drop for A {}
   |      ^^^^^
   |
   = note: see issue #67792 <https://github.com/rust-lang/rust/issues/67792> 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   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/const_drop_is_valid.rs:1:12
   |
LL | #![feature(effects)]
   |            ^^^^^^^
   |
   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
   = note: `#[warn(incomplete_features)]` on by default

error: using `#![feature(effects)]` without enabling next trait solver globally
   |
   = note: the next trait solver must be enabled globally for the effects feature to work correctly
   = help: use `-Znext-solver` to enable

error: const `impl` for trait `Drop` which is not marked with `#[const_trait]`
  --> $DIR/const_drop_is_valid.rs:6:12
   |
LL | impl const Drop for A {}
   |            ^^^^
   |
   = note: marking a trait with `#[const_trait]` ensures all default method bodies are `const`
   = note: adding a non-const method body in the future would be a breaking change

error[E0046]: not all trait items implemented, missing: `drop`
  --> $DIR/const_drop_is_valid.rs:6:1
   |
LL | impl const Drop for A {}
   | ^^^^^^^^^^^^^^^^^^^^^ missing `drop` in implementation
   |
   = help: implement the missing item: `fn drop(&mut self) { todo!() }`

error: aborting due to 4 previous errors; 1 warning emitted

Some errors have detailed explanations: E0046, E0658.
For more information about an error, try `rustc --explain E0046`.