From 1e584d2d6dee2bc72509574974bf7be11a5924f0 Mon Sep 17 00:00:00 2001 From: Vincenzo Palazzo Date: Sun, 24 Jul 2022 17:45:21 +0000 Subject: add suggestion when there is a impl of external trait on pointer Signed-off-by: Vincenzo Palazzo --- .../ui/errors/issue-99572-impl-trait-on-pointer.rs | 25 +++++++++++++++++ .../issue-99572-impl-trait-on-pointer.stderr | 31 ++++++++++++++++++++++ 2 files changed, 56 insertions(+) create mode 100644 src/test/ui/errors/issue-99572-impl-trait-on-pointer.rs create mode 100644 src/test/ui/errors/issue-99572-impl-trait-on-pointer.stderr (limited to 'src/test') diff --git a/src/test/ui/errors/issue-99572-impl-trait-on-pointer.rs b/src/test/ui/errors/issue-99572-impl-trait-on-pointer.rs new file mode 100644 index 00000000000..272c6bd3fb7 --- /dev/null +++ b/src/test/ui/errors/issue-99572-impl-trait-on-pointer.rs @@ -0,0 +1,25 @@ +// Emit additional suggestion to correct the trait implementation +// on a pointer +use std::{fmt, marker}; + +struct LocalType; + +impl fmt::Display for *mut LocalType { +//~^ ERROR only traits defined in the current crate can be implemented for arbitrary types +//~| NOTE impl doesn't use only types from inside the current crate +//~| NOTE `*mut LocalType` is not defined in the current crate because raw pointers are always foreign +//~| NOTE define and implement a trait or new type instead +//~| HELP consider introducing a new wrapper type + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "This not compile") + } +} + +impl marker::Copy for *mut T { +//~^ ERROR only traits defined in the current crate can be implemented for arbitrary types +//~| NOTE impl doesn't use only types from inside the current crate +//~| NOTE `*mut T` is not defined in the current crate because raw pointers are always foreign +//~| NOTE define and implement a trait or new type instead +} + +fn main() {} diff --git a/src/test/ui/errors/issue-99572-impl-trait-on-pointer.stderr b/src/test/ui/errors/issue-99572-impl-trait-on-pointer.stderr new file mode 100644 index 00000000000..78d7a47deaa --- /dev/null +++ b/src/test/ui/errors/issue-99572-impl-trait-on-pointer.stderr @@ -0,0 +1,31 @@ +error[E0117]: only traits defined in the current crate can be implemented for arbitrary types + --> $DIR/issue-99572-impl-trait-on-pointer.rs:7:1 + | +LL | impl fmt::Display for *mut LocalType { + | ^^^^^^^^^^^^^^^^^^^^^^-------------- + | | | + | | `*mut LocalType` is not defined in the current crate because raw pointers are always foreign + | impl doesn't use only types from inside the current crate + | + = note: define and implement a trait or new type instead +help: consider introducing a new wrapper type + | +LL + struct WrapperType(*mut LocalType); +LL + +LL ~ impl fmt::Display for WrapperType { + | + +error[E0117]: only traits defined in the current crate can be implemented for arbitrary types + --> $DIR/issue-99572-impl-trait-on-pointer.rs:18:1 + | +LL | impl marker::Copy for *mut T { + | ^^^^^^^^^^^^^^^^^^^^^^^^^------ + | | | + | | `*mut T` is not defined in the current crate because raw pointers are always foreign + | impl doesn't use only types from inside the current crate + | + = note: define and implement a trait or new type instead + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0117`. -- cgit 1.4.1-3-g733a5