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Diffstat (limited to 'src/test/ui/impl-trait/where-allowed.rs')
-rw-r--r-- | src/test/ui/impl-trait/where-allowed.rs | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/test/ui/impl-trait/where-allowed.rs b/src/test/ui/impl-trait/where-allowed.rs new file mode 100644 index 000000000..c1dd46c7f --- /dev/null +++ b/src/test/ui/impl-trait/where-allowed.rs @@ -0,0 +1,251 @@ +//! A simple test for testing many permutations of allowedness of +//! impl Trait +use std::fmt::Debug; + +// Allowed +fn in_parameters(_: impl Debug) { panic!() } + +// Allowed +fn in_return() -> impl Debug { panic!() } + +// Allowed +fn in_adt_in_parameters(_: Vec<impl Debug>) { panic!() } + +// Disallowed +fn in_fn_parameter_in_parameters(_: fn(impl Debug)) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_fn_return_in_parameters(_: fn() -> impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_fn_parameter_in_return() -> fn(impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_fn_return_in_return() -> fn() -> impl Debug { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_dyn_Fn_parameter_in_parameters(_: &dyn Fn(impl Debug)) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_dyn_Fn_return_in_parameters(_: &dyn Fn() -> impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_dyn_Fn_parameter_in_return() -> &'static dyn Fn(impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_dyn_Fn_return_in_return() -> &'static dyn Fn() -> impl Debug { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_impl_Fn_parameter_in_parameters(_: &impl Fn(impl Debug)) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +//~^^ ERROR nested `impl Trait` is not allowed + +// Disallowed +fn in_impl_Fn_return_in_parameters(_: &impl Fn() -> impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +//~| ERROR nested `impl Trait` is not allowed + +// Disallowed +fn in_impl_Fn_return_in_return() -> &'static impl Fn() -> impl Debug { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_Fn_parameter_in_generics<F: Fn(impl Debug)> (_: F) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +fn in_Fn_return_in_generics<F: Fn() -> impl Debug> (_: F) { panic!() } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + + +// Allowed +fn in_impl_Trait_in_parameters(_: impl Iterator<Item = impl Iterator>) { panic!() } + +// Allowed +fn in_impl_Trait_in_return() -> impl IntoIterator<Item = impl IntoIterator> { + vec![vec![0; 10], vec![12; 7], vec![8; 3]] +} + +// Disallowed +struct InBraceStructField { x: impl Debug } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +struct InAdtInBraceStructField { x: Vec<impl Debug> } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +struct InTupleStructField(impl Debug); +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +enum InEnum { + InBraceVariant { x: impl Debug }, + //~^ ERROR `impl Trait` only allowed in function and inherent method return types + InTupleVariant(impl Debug), + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Allowed +trait InTraitDefnParameters { + fn in_parameters(_: impl Debug); +} + +// Disallowed +trait InTraitDefnReturn { + fn in_return() -> impl Debug; + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Allowed and disallowed in trait impls +trait DummyTrait { + type Out; + fn in_trait_impl_parameter(_: impl Debug); + fn in_trait_impl_return() -> Self::Out; +} +impl DummyTrait for () { + type Out = impl Debug; + //~^ ERROR `impl Trait` in type aliases is unstable + + fn in_trait_impl_parameter(_: impl Debug) { } + // Allowed + + fn in_trait_impl_return() -> impl Debug { () } + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Allowed +struct DummyType; +impl DummyType { + fn in_inherent_impl_parameters(_: impl Debug) { } + fn in_inherent_impl_return() -> impl Debug { () } +} + +// Disallowed +extern "C" { + fn in_foreign_parameters(_: impl Debug); + //~^ ERROR `impl Trait` only allowed in function and inherent method return types + + fn in_foreign_return() -> impl Debug; + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Allowed +extern "C" fn in_extern_fn_parameters(_: impl Debug) { +} + +// Allowed +extern "C" fn in_extern_fn_return() -> impl Debug { + 22 +} + +type InTypeAlias<R> = impl Debug; +//~^ ERROR `impl Trait` in type aliases is unstable + +type InReturnInTypeAlias<R> = fn() -> impl Debug; +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +//~| ERROR `impl Trait` in type aliases is unstable + +// Disallowed in impl headers +impl PartialEq<impl Debug> for () { + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Disallowed in impl headers +impl PartialEq<()> for impl Debug { + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Disallowed in inherent impls +impl impl Debug { + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Disallowed in inherent impls +struct InInherentImplAdt<T> { t: T } +impl InInherentImplAdt<impl Debug> { + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} + +// Disallowed in where clauses +fn in_fn_where_clause() + where impl Debug: Debug +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +{ +} + +// Disallowed in where clauses +fn in_adt_in_fn_where_clause() + where Vec<impl Debug>: Debug +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +{ +} + +// Disallowed +fn in_trait_parameter_in_fn_where_clause<T>() + where T: PartialEq<impl Debug> +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +{ +} + +// Disallowed +fn in_Fn_parameter_in_fn_where_clause<T>() + where T: Fn(impl Debug) +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +{ +} + +// Disallowed +fn in_Fn_return_in_fn_where_clause<T>() + where T: Fn() -> impl Debug +//~^ ERROR `impl Trait` only allowed in function and inherent method return types +{ +} + +// Disallowed +struct InStructGenericParamDefault<T = impl Debug>(T); +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +enum InEnumGenericParamDefault<T = impl Debug> { Variant(T) } +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +trait InTraitGenericParamDefault<T = impl Debug> {} +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +type InTypeAliasGenericParamDefault<T = impl Debug> = T; +//~^ ERROR `impl Trait` only allowed in function and inherent method return types + +// Disallowed +impl <T = impl Debug> T {} +//~^ ERROR defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions +//~| WARNING this was previously accepted by the compiler but is being phased out +//~| ERROR `impl Trait` only allowed in function and inherent method return types +//~| ERROR no nominal type found + +// Disallowed +fn in_method_generic_param_default<T = impl Debug>(_: T) {} +//~^ ERROR defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions +//~| WARNING this was previously accepted by the compiler but is being phased out +//~| ERROR `impl Trait` only allowed in function and inherent method return types + +fn main() { + let _in_local_variable: impl Fn() = || {}; + //~^ ERROR `impl Trait` only allowed in function and inherent method return types + let _in_return_in_local_variable = || -> impl Fn() { || {} }; + //~^ ERROR `impl Trait` only allowed in function and inherent method return types +} |