Auto merge of #132329 - compiler-errors:fn-and-destruct, r=lcnr
Implement `~const Destruct` effect goal in the new solver This also fixed a subtle bug/limitation of the `NeedsConstDrop` check. Specifically, the "`Qualif`" API basically treats const drops as totally structural, even though dropping something that has an explicit `Drop` implementation cannot be structurally decomposed. For example: ```rust #![feature(const_trait_impl)] #[const_trait] trait Foo { fn foo(); } struct Conditional<T: Foo>(T); impl Foo for () { fn foo() { println!("uh oh"); } } impl<T> const Drop for Conditional<T> where T: ~const Foo { fn drop(&mut self) { T::foo(); } } const FOO: () = { let _ = Conditional(()); //~^ This should error. }; fn main() {} ``` In this example, when checking if the `Conditional(())` rvalue is const-drop, since `Conditional` has a const destructor, we would previously recurse into the `()` value and determine it has nothing to drop, which means that it is considered to *not* need a const drop -- even though dropping `Conditional(())` would mean evaluating the destructor which relies on that `T: const Foo` bound to hold! This could be fixed alternatively by banning any const conditions on `const Drop` impls, but that really sucks -- that means that basically no *interesting* const drop impls could be written. We have the capability to totally and intuitively support the right behavior, which I've implemented here.
This commit is contained in:
commit
743003b1a6
43 changed files with 525 additions and 231 deletions
|
@ -610,6 +610,7 @@ symbols! {
|
|||
const_compare_raw_pointers,
|
||||
const_constructor,
|
||||
const_deallocate,
|
||||
const_destruct,
|
||||
const_eval_limit,
|
||||
const_eval_select,
|
||||
const_evaluatable_checked,
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue