error[E0666]: nested `impl Trait` is not allowed --> $DIR/where-allowed.rs:49:51 | LL | fn in_impl_Fn_parameter_in_parameters(_: &impl Fn(impl Debug)) { panic!() } | --------^^^^^^^^^^- | | | | | nested `impl Trait` here | outer `impl Trait` error[E0666]: nested `impl Trait` is not allowed --> $DIR/where-allowed.rs:58:57 | LL | fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic!() } | --------^^^^^^^^^^- | | | | | nested `impl Trait` here | outer `impl Trait` error[E0658]: `impl Trait` in associated types is unstable --> $DIR/where-allowed.rs:120:16 | LL | type Out = impl Debug; | ^^^^^^^^^^ | = note: see issue #63063 for more information = help: add `#![feature(impl_trait_in_assoc_type)]` to the crate attributes to enable error[E0658]: `impl Trait` in type aliases is unstable --> $DIR/where-allowed.rs:155:23 | LL | type InTypeAlias = impl Debug; | ^^^^^^^^^^ | = note: see issue #63063 for more information = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable error[E0658]: `impl Trait` in type aliases is unstable --> $DIR/where-allowed.rs:158:39 | LL | type InReturnInTypeAlias = fn() -> impl Debug; | ^^^^^^^^^^ | = note: see issue #63063 for more information = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `fn` pointer params --> $DIR/where-allowed.rs:18:40 | LL | fn in_fn_parameter_in_parameters(_: fn(impl Debug)) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `fn` pointer return types --> $DIR/where-allowed.rs:22:42 | LL | fn in_fn_return_in_parameters(_: fn() -> impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `fn` pointer params --> $DIR/where-allowed.rs:26:38 | LL | fn in_fn_parameter_in_return() -> fn(impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `fn` pointer return types --> $DIR/where-allowed.rs:30:40 | LL | fn in_fn_return_in_return() -> fn() -> impl Debug { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:34:49 | LL | fn in_dyn_Fn_parameter_in_parameters(_: &dyn Fn(impl Debug)) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait return types --> $DIR/where-allowed.rs:38:51 | LL | fn in_dyn_Fn_return_in_parameters(_: &dyn Fn() -> impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:42:55 | LL | fn in_dyn_Fn_parameter_in_return() -> &'static dyn Fn(impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:49:51 | LL | fn in_impl_Fn_parameter_in_parameters(_: &impl Fn(impl Debug)) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait return types --> $DIR/where-allowed.rs:54:53 | LL | fn in_impl_Fn_return_in_parameters(_: &impl Fn() -> impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:58:57 | LL | fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:66:38 | LL | fn in_Fn_parameter_in_generics (_: F) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait return types --> $DIR/where-allowed.rs:70:40 | LL | fn in_Fn_return_in_generics impl Debug> (_: F) { panic!() } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in field types --> $DIR/where-allowed.rs:83:32 | LL | struct InBraceStructField { x: impl Debug } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in field types --> $DIR/where-allowed.rs:87:41 | LL | struct InAdtInBraceStructField { x: Vec } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in field types --> $DIR/where-allowed.rs:91:27 | LL | struct InTupleStructField(impl Debug); | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in field types --> $DIR/where-allowed.rs:96:25 | LL | InBraceVariant { x: impl Debug }, | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in field types --> $DIR/where-allowed.rs:98:20 | LL | InTupleVariant(impl Debug), | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in trait method return types --> $DIR/where-allowed.rs:109:23 | LL | fn in_return() -> impl Debug; | ^^^^^^^^^^ | = note: see issue #91611 for more information = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `impl` method return types --> $DIR/where-allowed.rs:126:34 | LL | fn in_trait_impl_return() -> impl Debug { () } | ^^^^^^^^^^ | = note: see issue #91611 for more information = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `extern fn` params --> $DIR/where-allowed.rs:139:33 | LL | fn in_foreign_parameters(_: impl Debug); | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `extern fn` return types --> $DIR/where-allowed.rs:142:31 | LL | fn in_foreign_return() -> impl Debug; | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `fn` pointer return types --> $DIR/where-allowed.rs:158:39 | LL | type InReturnInTypeAlias = fn() -> impl Debug; | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in traits --> $DIR/where-allowed.rs:163:16 | LL | impl PartialEq for () { | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in impl headers --> $DIR/where-allowed.rs:168:24 | LL | impl PartialEq<()> for impl Debug { | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in impl headers --> $DIR/where-allowed.rs:173:6 | LL | impl impl Debug { | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in impl headers --> $DIR/where-allowed.rs:179:24 | LL | impl InInherentImplAdt { | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in bounds --> $DIR/where-allowed.rs:185:11 | LL | where impl Debug: Debug | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in bounds --> $DIR/where-allowed.rs:192:15 | LL | where Vec: Debug | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in bounds --> $DIR/where-allowed.rs:199:24 | LL | where T: PartialEq | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait params --> $DIR/where-allowed.rs:206:17 | LL | where T: Fn(impl Debug) | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in `Fn` trait return types --> $DIR/where-allowed.rs:213:22 | LL | where T: Fn() -> impl Debug | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:219:40 | LL | struct InStructGenericParamDefault(T); | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:223:36 | LL | enum InEnumGenericParamDefault { Variant(T) } | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:227:38 | LL | trait InTraitGenericParamDefault {} | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:231:41 | LL | type InTypeAliasGenericParamDefault = T; | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:235:11 | LL | impl T {} | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in generic parameter defaults --> $DIR/where-allowed.rs:242:40 | LL | fn in_method_generic_param_default(_: T) {} | ^^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in variable bindings --> $DIR/where-allowed.rs:248:29 | LL | let _in_local_variable: impl Fn() = || {}; | ^^^^^^^^^ error[E0562]: `impl Trait` only allowed in function and inherent method argument and return types, not in closure return types --> $DIR/where-allowed.rs:250:46 | LL | let _in_return_in_local_variable = || -> impl Fn() { || {} }; | ^^^^^^^^^ error: defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions --> $DIR/where-allowed.rs:235:7 | LL | impl T {} | ^^^^^^^^^^^^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #36887 = note: `#[deny(invalid_type_param_default)]` on by default error: defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions --> $DIR/where-allowed.rs:242:36 | LL | fn in_method_generic_param_default(_: T) {} | ^^^^^^^^^^^^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #36887 error[E0118]: no nominal type found for inherent implementation --> $DIR/where-allowed.rs:235:1 | LL | impl T {} | ^^^^^^^^^^^^^^^^^^^^^^^ impl requires a nominal type | = note: either implement a trait on it or create a newtype to wrap it instead error: aborting due to 47 previous errors Some errors have detailed explanations: E0118, E0562, E0658, E0666. For more information about an error, try `rustc --explain E0118`.