error[E0277]: can't compare `*const ()` with `*const ()` in const contexts --> $DIR/issue-25826.rs:3:52 | LL | const A: bool = unsafe { id:: as *const () < id:: as *const () }; | ^ no implementation for `*const () < *const ()` and `*const () > *const ()` | = help: the trait `~const PartialOrd` is not implemented for `*const ()` note: the trait `PartialOrd` is implemented for `*const ()`, but that implementation is not `const` --> $DIR/issue-25826.rs:3:52 | LL | const A: bool = unsafe { id:: as *const () < id:: as *const () }; | ^ help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement | LL | fn main() where *const (): ~const PartialOrd { | ++++++++++++++++++++++++++++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.