diff options
4 files changed, 44 insertions, 4 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes.rs b/compiler/rustc_error_codes/src/error_codes.rs index 1b4b58314b3..cd846d63de8 100644 --- a/compiler/rustc_error_codes/src/error_codes.rs +++ b/compiler/rustc_error_codes/src/error_codes.rs @@ -92,6 +92,7 @@ E0164: include_str!("./error_codes/E0164.md"), E0165: include_str!("./error_codes/E0165.md"), E0170: include_str!("./error_codes/E0170.md"), E0178: include_str!("./error_codes/E0178.md"), +E0183: include_str!("./error_codes/E0183.md"), E0184: include_str!("./error_codes/E0184.md"), E0185: include_str!("./error_codes/E0185.md"), E0186: include_str!("./error_codes/E0186.md"), @@ -512,7 +513,6 @@ E0785: include_str!("./error_codes/E0785.md"), // E0173, // manual implementations of unboxed closure traits are experimental // E0174, // E0182, // merged into E0229 - E0183, // E0187, // cannot infer the kind of the closure // E0188, // can not cast an immutable reference to a mutable pointer // E0189, // deprecated: can only cast a boxed pointer to a boxed object diff --git a/compiler/rustc_error_codes/src/error_codes/E0183.md b/compiler/rustc_error_codes/src/error_codes/E0183.md new file mode 100644 index 00000000000..7e1d08daae1 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0183.md @@ -0,0 +1,39 @@ +Manual implemetation of a `Fn*` trait. + +Erroneous code example: + +```compile_fail,E0183 +struct MyClosure { + foo: i32 +} + +impl FnOnce<()> for MyClosure { // error + type Output = (); + extern "rust-call" fn call_once(self, args: ()) -> Self::Output { + println!("{}", self.foo); + } +} +``` + +Manually implementing `Fn`, `FnMut` or `FnOnce` is unstable +and requires `#![feature(fn_traits, unboxed_closures)]`. + +``` +#![feature(fn_traits, unboxed_closures)] + +struct MyClosure { + foo: i32 +} + +impl FnOnce<()> for MyClosure { // ok! + type Output = (); + extern "rust-call" fn call_once(self, args: ()) -> Self::Output { + println!("{}", self.foo); + } +} +``` + +The argumements must be a tuple representing the argument list. +For more info, see the [tracking issue][iss29625]: + +[iss29625]: https://github.com/rust-lang/rust/issues/29625 diff --git a/src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr b/src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr index 22a1ce30618..e0e0acadb37 100644 --- a/src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr +++ b/src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr @@ -101,5 +101,5 @@ LL | impl FnOnce<()> for Baz { error: aborting due to 12 previous errors -Some errors have detailed explanations: E0229, E0658. -For more information about an error, try `rustc --explain E0229`. +Some errors have detailed explanations: E0183, E0229, E0658. +For more information about an error, try `rustc --explain E0183`. diff --git a/src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr b/src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr index 2c8915d0ac3..8c5f8796456 100644 --- a/src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr +++ b/src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr @@ -26,4 +26,5 @@ LL | impl FnOnce<(u32, u32)> for Test { error: aborting due to 3 previous errors -For more information about this error, try `rustc --explain E0658`. +Some errors have detailed explanations: E0183, E0658. +For more information about an error, try `rustc --explain E0183`. |