diff --git a/compiler/rustc_error_codes/src/error_codes/E0091.md b/compiler/rustc_error_codes/src/error_codes/E0091.md index 03cb32803715e..3bf4e907ecb1f 100644 --- a/compiler/rustc_error_codes/src/error_codes/E0091.md +++ b/compiler/rustc_error_codes/src/error_codes/E0091.md @@ -1,11 +1,11 @@ -An unnecessary type or const parameter was given in a type alias. +An unnecessary type parameter was given in a type alias. Erroneous code example: ```compile_fail,E0091 -type Foo = u32; // error: type parameter `T` is unused +type Foo = u32; // error: type parameter `T` is never used // or: -type Foo = Box; // error: type parameter `B` is unused +type Foo = Box; // error: type parameter `B` is never used ``` Please check you didn't write too many parameters. Example: diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl index 432c9c12cbfbc..54d0fb6ffab72 100644 --- a/compiler/rustc_hir_analysis/messages.ftl +++ b/compiler/rustc_hir_analysis/messages.ftl @@ -434,6 +434,17 @@ hir_analysis_unused_associated_type_bounds = .note = this associated type has a `where Self: Sized` bound. Thus, while the associated type can be specified, it cannot be used in any way, because trait objects are not `Sized`. .suggestion = remove this bound +hir_analysis_unused_generic_parameter = + {$param_def_kind} `{$param_name}` is never used + .label = unused {$param_def_kind} + .const_param_help = if you intended `{$param_name}` to be a const parameter, use `const {$param_name}: /* Type */` instead +hir_analysis_unused_generic_parameter_adt_help = + consider removing `{$param_name}`, referring to it in a field, or using a marker such as `{$phantom_data}` +hir_analysis_unused_generic_parameter_adt_no_phantom_data_help = + consider removing `{$param_name}` or referring to it in a field +hir_analysis_unused_generic_parameter_ty_alias_help = + consider removing `{$param_name}` or referring to it in the body of the type alias + hir_analysis_value_of_associated_struct_already_specified = the value of the associated type `{$item_name}` in trait `{$def_path}` is already specified .label = re-bound here diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index 2fe3499e8e690..50809a571b8dc 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -31,6 +31,7 @@ use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _; use rustc_trait_selection::traits::{self, TraitEngine, TraitEngineExt as _}; use rustc_type_ir::fold::TypeFoldable; +use std::cell::LazyCell; use std::ops::ControlFlow; pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) { @@ -520,9 +521,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) { } } DefKind::TyAlias => { - let pty_ty = tcx.type_of(def_id).instantiate_identity(); - let generics = tcx.generics_of(def_id); - check_type_params_are_used(tcx, generics, pty_ty); + check_type_alias_type_params_are_used(tcx, def_id); } DefKind::ForeignMod => { let it = tcx.hir().expect_item(def_id); @@ -1269,28 +1268,51 @@ fn detect_discriminant_duplicate<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>) } } -pub(super) fn check_type_params_are_used<'tcx>( - tcx: TyCtxt<'tcx>, - generics: &ty::Generics, - ty: Ty<'tcx>, -) { - debug!("check_type_params_are_used(generics={:?}, ty={:?})", generics, ty); - - assert_eq!(generics.parent, None); +fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) { + if tcx.type_alias_is_lazy(def_id) { + // Since we compute the variances for lazy type aliases and already reject bivariant + // parameters as unused, we can and should skip this check for lazy type aliases. + return; + } + let generics = tcx.generics_of(def_id); if generics.own_counts().types == 0 { return; } - let mut params_used = BitSet::new_empty(generics.params.len()); - + let ty = tcx.type_of(def_id).instantiate_identity(); if ty.references_error() { - // If there is already another error, do not emit - // an error for not using a type parameter. + // If there is already another error, do not emit an error for not using a type parameter. assert!(tcx.dcx().has_errors().is_some()); return; } + // Lazily calculated because it is only needed in case of an error. + let bounded_params = LazyCell::new(|| { + tcx.explicit_predicates_of(def_id) + .predicates + .iter() + .filter_map(|(predicate, span)| { + let bounded_ty = match predicate.kind().skip_binder() { + ty::ClauseKind::Trait(pred) => pred.trait_ref.self_ty(), + ty::ClauseKind::TypeOutlives(pred) => pred.0, + _ => return None, + }; + if let ty::Param(param) = bounded_ty.kind() { + Some((param.index, span)) + } else { + None + } + }) + // FIXME: This assumes that elaborated `Sized` bounds come first (which does hold at the + // time of writing). This is a bit fragile since we later use the span to detect elaborated + // `Sized` bounds. If they came last for example, this would break `Trait + /*elab*/Sized` + // since it would overwrite the span of the user-written bound. This could be fixed by + // folding the spans with `Span::to` which requires a bit of effort I think. + .collect::>() + }); + + let mut params_used = BitSet::new_empty(generics.params.len()); for leaf in ty.walk() { if let GenericArgKind::Type(leaf_ty) = leaf.unpack() && let ty::Param(param) = leaf_ty.kind() @@ -1305,15 +1327,24 @@ pub(super) fn check_type_params_are_used<'tcx>( && let ty::GenericParamDefKind::Type { .. } = param.kind { let span = tcx.def_span(param.def_id); - struct_span_code_err!( - tcx.dcx(), + let param_name = Ident::new(param.name, span); + + // The corresponding predicates are post-`Sized`-elaboration. Therefore we + // * check for emptiness to detect lone user-written `?Sized` bounds + // * compare the param span to the pred span to detect lone user-written `Sized` bounds + let has_explicit_bounds = bounded_params.is_empty() + || (*bounded_params).get(¶m.index).is_some_and(|&&pred_sp| pred_sp != span); + let const_param_help = (!has_explicit_bounds).then_some(()); + + let mut diag = tcx.dcx().create_err(errors::UnusedGenericParameter { span, - E0091, - "type parameter `{}` is unused", - param.name, - ) - .with_span_label(span, "unused type parameter") - .emit(); + param_name, + param_def_kind: tcx.def_descr(param.def_id), + help: errors::UnusedGenericParameterHelp::TyAlias { param_name }, + const_param_help, + }); + diag.code(E0091); + diag.emit(); } } } diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index b0510f9a75b3b..885cfbd0fe224 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -1,11 +1,10 @@ use crate::autoderef::Autoderef; use crate::constrained_generic_params::{identify_constrained_generic_params, Parameter}; +use crate::errors; use rustc_ast as ast; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet}; -use rustc_errors::{ - codes::*, pluralize, struct_span_code_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, -}; +use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed}; use rustc_hir as hir; use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId}; use rustc_hir::lang_items::LangItem; @@ -21,7 +20,7 @@ use rustc_middle::ty::{ }; use rustc_middle::ty::{GenericArgKind, GenericArgs}; use rustc_session::parse::feature_err; -use rustc_span::symbol::{sym, Ident, Symbol}; +use rustc_span::symbol::{sym, Ident}; use rustc_span::{Span, DUMMY_SP}; use rustc_target::spec::abi::Abi; use rustc_trait_selection::regions::InferCtxtRegionExt; @@ -1869,7 +1868,7 @@ fn check_variances_for_type_defn<'tcx>( hir::ParamName::Error => {} _ => { let has_explicit_bounds = explicitly_bounded_params.contains(¶meter); - report_bivariance(tcx, hir_param, has_explicit_bounds); + report_bivariance(tcx, hir_param, has_explicit_bounds, item.kind); } } } @@ -1879,30 +1878,38 @@ fn report_bivariance( tcx: TyCtxt<'_>, param: &rustc_hir::GenericParam<'_>, has_explicit_bounds: bool, + item_kind: ItemKind<'_>, ) -> ErrorGuaranteed { - let span = param.span; - let param_name = param.name.ident().name; - let mut err = error_392(tcx, span, param_name); - - let suggested_marker_id = tcx.lang_items().phantom_data(); - // Help is available only in presence of lang items. - let msg = if let Some(def_id) = suggested_marker_id { - format!( - "consider removing `{}`, referring to it in a field, or using a marker such as `{}`", - param_name, - tcx.def_path_str(def_id), - ) - } else { - format!("consider removing `{param_name}` or referring to it in a field") + let param_name = param.name.ident(); + + let help = match item_kind { + ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => { + if let Some(def_id) = tcx.lang_items().phantom_data() { + errors::UnusedGenericParameterHelp::Adt { + param_name, + phantom_data: tcx.def_path_str(def_id), + } + } else { + errors::UnusedGenericParameterHelp::AdtNoPhantomData { param_name } + } + } + ItemKind::TyAlias(..) => errors::UnusedGenericParameterHelp::TyAlias { param_name }, + item_kind => bug!("report_bivariance: unexpected item kind: {item_kind:?}"), }; - err.help(msg); - if matches!(param.kind, hir::GenericParamKind::Type { .. }) && !has_explicit_bounds { - err.help(format!( - "if you intended `{param_name}` to be a const parameter, use `const {param_name}: usize` instead" - )); - } - err.emit() + let const_param_help = + matches!(param.kind, hir::GenericParamKind::Type { .. } if !has_explicit_bounds) + .then_some(()); + + let mut diag = tcx.dcx().create_err(errors::UnusedGenericParameter { + span: param.span, + param_name, + param_def_kind: tcx.def_descr(param.def_id.to_def_id()), + help, + const_param_help, + }); + diag.code(E0392); + diag.emit() } impl<'tcx> WfCheckingCtxt<'_, 'tcx> { @@ -1967,11 +1974,6 @@ fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalModDefId) -> Result<(), Error res } -fn error_392(tcx: TyCtxt<'_>, span: Span, param_name: Symbol) -> DiagnosticBuilder<'_> { - struct_span_code_err!(tcx.dcx(), span, E0392, "parameter `{param_name}` is never used") - .with_span_label(span, "unused parameter") -} - pub fn provide(providers: &mut Providers) { *providers = Providers { check_mod_type_wf, check_well_formed, ..*providers }; } diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs index e5871276d6414..4eba31e327f68 100644 --- a/compiler/rustc_hir_analysis/src/errors.rs +++ b/compiler/rustc_hir_analysis/src/errors.rs @@ -1511,3 +1511,27 @@ pub struct NotSupportedDelegation<'a> { #[label] pub callee_span: Span, } + +#[derive(Diagnostic)] +#[diag(hir_analysis_unused_generic_parameter)] +pub(crate) struct UnusedGenericParameter { + #[primary_span] + #[label] + pub span: Span, + pub param_name: Ident, + pub param_def_kind: &'static str, + #[subdiagnostic] + pub help: UnusedGenericParameterHelp, + #[help(hir_analysis_const_param_help)] + pub const_param_help: Option<()>, +} + +#[derive(Subdiagnostic)] +pub(crate) enum UnusedGenericParameterHelp { + #[help(hir_analysis_unused_generic_parameter_adt_help)] + Adt { param_name: Ident, phantom_data: String }, + #[help(hir_analysis_unused_generic_parameter_adt_no_phantom_data_help)] + AdtNoPhantomData { param_name: Ident }, + #[help(hir_analysis_unused_generic_parameter_ty_alias_help)] + TyAlias { param_name: Ident }, +} diff --git a/tests/ui/const-generics/generic_arg_infer/infer-arg-test.stderr b/tests/ui/const-generics/generic_arg_infer/infer-arg-test.stderr index a6b736261e09c..6d8dd017734c0 100644 --- a/tests/ui/const-generics/generic_arg_infer/infer-arg-test.stderr +++ b/tests/ui/const-generics/generic_arg_infer/infer-arg-test.stderr @@ -10,14 +10,14 @@ error: expected identifier, found reserved identifier `_` LL | fn bad_infer_fn<_>() {} | ^ expected identifier, found reserved identifier -error[E0392]: parameter `_` is never used +error[E0392]: type parameter `_` is never used --> $DIR/infer-arg-test.rs:7:17 | LL | struct BadInfer<_>; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `_`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `_` to be a const parameter, use `const _: usize` instead + = help: if you intended `_` to be a const parameter, use `const _: /* Type */` instead error[E0107]: struct takes 2 generic arguments but 3 generic arguments were supplied --> $DIR/infer-arg-test.rs:18:10 diff --git a/tests/ui/const-generics/issue-46511.stderr b/tests/ui/const-generics/issue-46511.stderr index d57295fa2fae1..75d59ee40b3b7 100644 --- a/tests/ui/const-generics/issue-46511.stderr +++ b/tests/ui/const-generics/issue-46511.stderr @@ -7,11 +7,11 @@ LL | _a: [u8; std::mem::size_of::<&'a mut u8>()] = note: lifetime parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/issue-46511.rs:3:12 | LL | struct Foo<'a> - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/const-generics/issues/issue-67375.min.stderr b/tests/ui/const-generics/issues/issue-67375.min.stderr index 7671e3c468876..e871203ed9b89 100644 --- a/tests/ui/const-generics/issues/issue-67375.min.stderr +++ b/tests/ui/const-generics/issues/issue-67375.min.stderr @@ -7,14 +7,14 @@ LL | inner: [(); { [|_: &T| {}; 0].len() }], = note: type parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-67375.rs:5:12 | LL | struct Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/const-generics/issues/issue-67945-1.min.stderr b/tests/ui/const-generics/issues/issue-67945-1.min.stderr index 1d071da903fa1..1de607644f570 100644 --- a/tests/ui/const-generics/issues/issue-67945-1.min.stderr +++ b/tests/ui/const-generics/issues/issue-67945-1.min.stderr @@ -16,14 +16,14 @@ LL | let b = &*(&x as *const _ as *const S); = note: type parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions -error[E0392]: parameter `S` is never used +error[E0392]: type parameter `S` is never used --> $DIR/issue-67945-1.rs:7:12 | LL | struct Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `S` to be a const parameter, use `const S: usize` instead + = help: if you intended `S` to be a const parameter, use `const S: /* Type */` instead error: aborting due to 3 previous errors diff --git a/tests/ui/const-generics/issues/issue-67945-3.min.stderr b/tests/ui/const-generics/issues/issue-67945-3.min.stderr index e34869c79386b..0ccba18e953cf 100644 --- a/tests/ui/const-generics/issues/issue-67945-3.min.stderr +++ b/tests/ui/const-generics/issues/issue-67945-3.min.stderr @@ -7,14 +7,14 @@ LL | let x: Option = None; = note: type parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions -error[E0392]: parameter `S` is never used +error[E0392]: type parameter `S` is never used --> $DIR/issue-67945-3.rs:9:12 | LL | struct Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `S` to be a const parameter, use `const S: usize` instead + = help: if you intended `S` to be a const parameter, use `const S: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/const-generics/issues/issue-67945-4.min.stderr b/tests/ui/const-generics/issues/issue-67945-4.min.stderr index 280c6f4f2cdfe..83ae68e2dbf0e 100644 --- a/tests/ui/const-generics/issues/issue-67945-4.min.stderr +++ b/tests/ui/const-generics/issues/issue-67945-4.min.stderr @@ -7,14 +7,14 @@ LL | let x: Option> = None; = note: type parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions -error[E0392]: parameter `S` is never used +error[E0392]: type parameter `S` is never used --> $DIR/issue-67945-4.rs:8:12 | LL | struct Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `S` to be a const parameter, use `const S: usize` instead + = help: if you intended `S` to be a const parameter, use `const S: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/const-generics/unused-type-param-suggestion.rs b/tests/ui/const-generics/unused-type-param-suggestion.rs index 2251512c4596e..fb0ccb4fdcd72 100644 --- a/tests/ui/const-generics/unused-type-param-suggestion.rs +++ b/tests/ui/const-generics/unused-type-param-suggestion.rs @@ -1,4 +1,27 @@ #![crate_type="lib"] -struct Example; -//~^ ERROR parameter +struct S; +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` +//~| HELP if you intended `N` to be a const parameter + +// Ensure that we don't emit the const param suggestion here: +struct T; +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` + +type A = (); +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` +//~| HELP if you intended `N` to be a const parameter + +// Ensure that we don't emit the const param suggestion here: +type B = (); +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` +type C = (); +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` +type D = (); +//~^ ERROR type parameter `N` is never used +//~| HELP consider removing `N` diff --git a/tests/ui/const-generics/unused-type-param-suggestion.stderr b/tests/ui/const-generics/unused-type-param-suggestion.stderr index 6e985f56666bd..67b704d8bc725 100644 --- a/tests/ui/const-generics/unused-type-param-suggestion.stderr +++ b/tests/ui/const-generics/unused-type-param-suggestion.stderr @@ -1,12 +1,54 @@ -error[E0392]: parameter `N` is never used - --> $DIR/unused-type-param-suggestion.rs:3:16 +error[E0392]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:3:10 | -LL | struct Example; - | ^ unused parameter +LL | struct S; + | ^ unused type parameter | = help: consider removing `N`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `N` to be a const parameter, use `const N: usize` instead + = help: if you intended `N` to be a const parameter, use `const N: /* Type */` instead -error: aborting due to 1 previous error +error[E0392]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:9:10 + | +LL | struct T; + | ^ unused type parameter + | + = help: consider removing `N`, referring to it in a field, or using a marker such as `PhantomData` + +error[E0091]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:13:8 + | +LL | type A = (); + | ^ unused type parameter + | + = help: consider removing `N` or referring to it in the body of the type alias + = help: if you intended `N` to be a const parameter, use `const N: /* Type */` instead + +error[E0091]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:19:8 + | +LL | type B = (); + | ^ unused type parameter + | + = help: consider removing `N` or referring to it in the body of the type alias + +error[E0091]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:22:8 + | +LL | type C = (); + | ^ unused type parameter + | + = help: consider removing `N` or referring to it in the body of the type alias + +error[E0091]: type parameter `N` is never used + --> $DIR/unused-type-param-suggestion.rs:25:8 + | +LL | type D = (); + | ^ unused type parameter + | + = help: consider removing `N` or referring to it in the body of the type alias + +error: aborting due to 6 previous errors -For more information about this error, try `rustc --explain E0392`. +Some errors have detailed explanations: E0091, E0392. +For more information about an error, try `rustc --explain E0091`. diff --git a/tests/ui/enum-discriminant/issue-70453-generics-in-discr-ice.stderr b/tests/ui/enum-discriminant/issue-70453-generics-in-discr-ice.stderr index fac3ce07aeb92..1341b03cb56e4 100644 --- a/tests/ui/enum-discriminant/issue-70453-generics-in-discr-ice.stderr +++ b/tests/ui/enum-discriminant/issue-70453-generics-in-discr-ice.stderr @@ -6,14 +6,14 @@ LL | Some = std::mem::size_of::(), | = note: type parameters may not be used in enum discriminant values -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-70453-generics-in-discr-ice.rs:7:20 | LL | enum MyWeirdOption { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/enum/issue-67945-1.stderr b/tests/ui/enum/issue-67945-1.stderr index 878fa322f02d5..ce0ea77763663 100644 --- a/tests/ui/enum/issue-67945-1.stderr +++ b/tests/ui/enum/issue-67945-1.stderr @@ -6,14 +6,14 @@ LL | let x: S = 0; | = note: type parameters may not be used in enum discriminant values -error[E0392]: parameter `S` is never used +error[E0392]: type parameter `S` is never used --> $DIR/issue-67945-1.rs:1:10 | LL | enum Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `S` to be a const parameter, use `const S: usize` instead + = help: if you intended `S` to be a const parameter, use `const S: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/enum/issue-67945-2.stderr b/tests/ui/enum/issue-67945-2.stderr index f8ec12d470acf..96bd08f841a40 100644 --- a/tests/ui/enum/issue-67945-2.stderr +++ b/tests/ui/enum/issue-67945-2.stderr @@ -6,14 +6,14 @@ LL | Var = type_ascribe!(0, S), | = note: type parameters may not be used in enum discriminant values -error[E0392]: parameter `S` is never used +error[E0392]: type parameter `S` is never used --> $DIR/issue-67945-2.rs:3:10 | LL | enum Bug { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `S` to be a const parameter, use `const S: usize` instead + = help: if you intended `S` to be a const parameter, use `const S: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/error-codes/E0091.stderr b/tests/ui/error-codes/E0091.stderr index a596b75e481de..c1427ec66863a 100644 --- a/tests/ui/error-codes/E0091.stderr +++ b/tests/ui/error-codes/E0091.stderr @@ -1,14 +1,20 @@ -error[E0091]: type parameter `T` is unused +error[E0091]: type parameter `T` is never used --> $DIR/E0091.rs:1:10 | LL | type Foo = u32; | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead -error[E0091]: type parameter `B` is unused +error[E0091]: type parameter `B` is never used --> $DIR/E0091.rs:2:14 | LL | type Foo2 = Box; | ^ unused type parameter + | + = help: consider removing `B` or referring to it in the body of the type alias + = help: if you intended `B` to be a const parameter, use `const B: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/error-codes/E0392.stderr b/tests/ui/error-codes/E0392.stderr index ecbfd5584d5a3..9971267e9270d 100644 --- a/tests/ui/error-codes/E0392.stderr +++ b/tests/ui/error-codes/E0392.stderr @@ -1,11 +1,11 @@ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/E0392.rs:1:10 | LL | enum Foo { Bar } - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 1 previous error diff --git a/tests/ui/inner-static-type-parameter.stderr b/tests/ui/inner-static-type-parameter.stderr index ff6558e494b11..6c7f1ffbe1690 100644 --- a/tests/ui/inner-static-type-parameter.stderr +++ b/tests/ui/inner-static-type-parameter.stderr @@ -6,14 +6,14 @@ LL | fn foo() { LL | static a: Bar = Bar::What; | ^ use of generic parameter from outer item -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/inner-static-type-parameter.rs:3:10 | LL | enum Bar { What } - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/issues/issue-17904-2.stderr b/tests/ui/issues/issue-17904-2.stderr index 102c8537f8e04..9965106d1401a 100644 --- a/tests/ui/issues/issue-17904-2.stderr +++ b/tests/ui/issues/issue-17904-2.stderr @@ -1,8 +1,8 @@ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-17904-2.rs:4:12 | LL | struct Foo where T: Copy; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/issues/issue-17994.rs b/tests/ui/issues/issue-17994.rs index 39b0a7ebe74d8..ab37a172eaa74 100644 --- a/tests/ui/issues/issue-17994.rs +++ b/tests/ui/issues/issue-17994.rs @@ -1,3 +1,3 @@ trait Tr {} -type Huh where T: Tr = isize; //~ ERROR type parameter `T` is unused +type Huh where T: Tr = isize; //~ ERROR type parameter `T` is never used fn main() {} diff --git a/tests/ui/issues/issue-17994.stderr b/tests/ui/issues/issue-17994.stderr index ba3def64dfb5d..f149e5d08faac 100644 --- a/tests/ui/issues/issue-17994.stderr +++ b/tests/ui/issues/issue-17994.stderr @@ -1,8 +1,10 @@ -error[E0091]: type parameter `T` is unused +error[E0091]: type parameter `T` is never used --> $DIR/issue-17994.rs:2:10 | LL | type Huh where T: Tr = isize; | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias error: aborting due to 1 previous error diff --git a/tests/ui/issues/issue-20413.stderr b/tests/ui/issues/issue-20413.stderr index 8793029dd224a..5d442eb989851 100644 --- a/tests/ui/issues/issue-20413.stderr +++ b/tests/ui/issues/issue-20413.stderr @@ -1,11 +1,11 @@ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-20413.rs:6:15 | LL | struct NoData; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error[E0275]: overflow evaluating the requirement `NoData>>>>>>: Foo` --> $DIR/issue-20413.rs:9:36 diff --git a/tests/ui/issues/issue-30236.rs b/tests/ui/issues/issue-30236.rs index 9c2d855076d79..08d08a544021e 100644 --- a/tests/ui/issues/issue-30236.rs +++ b/tests/ui/issues/issue-30236.rs @@ -1,5 +1,5 @@ type Foo< - Unused //~ ERROR type parameter `Unused` is unused + Unused //~ ERROR type parameter `Unused` is never used > = u8; fn main() { diff --git a/tests/ui/issues/issue-30236.stderr b/tests/ui/issues/issue-30236.stderr index 0f69f49f505a0..bfe374a653f5f 100644 --- a/tests/ui/issues/issue-30236.stderr +++ b/tests/ui/issues/issue-30236.stderr @@ -1,8 +1,11 @@ -error[E0091]: type parameter `Unused` is unused +error[E0091]: type parameter `Unused` is never used --> $DIR/issue-30236.rs:2:5 | LL | Unused | ^^^^^^ unused type parameter + | + = help: consider removing `Unused` or referring to it in the body of the type alias + = help: if you intended `Unused` to be a const parameter, use `const Unused: /* Type */` instead error: aborting due to 1 previous error diff --git a/tests/ui/issues/issue-31910.stderr b/tests/ui/issues/issue-31910.stderr index 89a6d5574a1e5..ca2d2f619e62e 100644 --- a/tests/ui/issues/issue-31910.stderr +++ b/tests/ui/issues/issue-31910.stderr @@ -4,11 +4,11 @@ error[E0308]: mismatched types LL | X = Trait::Number, | ^^^^^^^^^^^^^ expected `isize`, found `i32` -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-31910.rs:1:11 | LL | enum Enum { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/issues/issue-34373.stderr b/tests/ui/issues/issue-34373.stderr index 1a1cfc925b779..13667cd920e9b 100644 --- a/tests/ui/issues/issue-34373.stderr +++ b/tests/ui/issues/issue-34373.stderr @@ -45,14 +45,14 @@ help: alternatively, consider constraining `foo` so it does not apply to trait o LL | fn foo(_: T) where Self: Sized {} | +++++++++++++++++ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-34373.rs:7:16 | LL | pub struct Foo>>; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ unused parameter + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 3 previous errors diff --git a/tests/ui/issues/issue-36299.stderr b/tests/ui/issues/issue-36299.stderr index dc24fb353f408..29e8d7ca59a24 100644 --- a/tests/ui/issues/issue-36299.stderr +++ b/tests/ui/issues/issue-36299.stderr @@ -1,19 +1,19 @@ -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/issue-36299.rs:1:12 | LL | struct Foo<'a, A> {} - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `A` is never used +error[E0392]: type parameter `A` is never used --> $DIR/issue-36299.rs:1:16 | LL | struct Foo<'a, A> {} - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `A`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `A` to be a const parameter, use `const A: usize` instead + = help: if you intended `A` to be a const parameter, use `const A: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/issues/issue-37534.stderr b/tests/ui/issues/issue-37534.stderr index 03fea2c16486d..a687e733d3dae 100644 --- a/tests/ui/issues/issue-37534.stderr +++ b/tests/ui/issues/issue-37534.stderr @@ -15,11 +15,11 @@ warning: relaxing a default bound only does something for `?Sized`; all other tr LL | struct Foo {} | ^^^^^ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/issue-37534.rs:1:12 | LL | struct Foo {} - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/lang-items/lang-item-generic-requirements.stderr b/tests/ui/lang-items/lang-item-generic-requirements.stderr index 8072e6797e49c..30abdf84046ea 100644 --- a/tests/ui/lang-items/lang-item-generic-requirements.stderr +++ b/tests/ui/lang-items/lang-item-generic-requirements.stderr @@ -50,23 +50,23 @@ LL | LL | fn start(_: *const u8, _: isize, _: *const *const u8) -> isize { | - this function has 0 generic arguments -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/lang-item-generic-requirements.rs:24:22 | LL | struct MyPhantomData; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T` or referring to it in a field - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead -error[E0392]: parameter `U` is never used +error[E0392]: type parameter `U` is never used --> $DIR/lang-item-generic-requirements.rs:24:25 | LL | struct MyPhantomData; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `U` or referring to it in a field - = help: if you intended `U` to be a const parameter, use `const U: usize` instead + = help: if you intended `U` to be a const parameter, use `const U: /* Type */` instead error[E0369]: cannot add `{integer}` to `{integer}` --> $DIR/lang-item-generic-requirements.rs:44:7 diff --git a/tests/ui/lazy-type-alias/unused-generic-parameters.rs b/tests/ui/lazy-type-alias/unused-generic-parameters.rs new file mode 100644 index 0000000000000..9d02de7a7212b --- /dev/null +++ b/tests/ui/lazy-type-alias/unused-generic-parameters.rs @@ -0,0 +1,22 @@ +// Check that we reject bivariant generic parameters as unused. +// Furthermore, check that we only emit a single diagnostic for unused type parameters: +// Previously, we would emit *two* errors, namely E0392 and E0091. + +#![feature(lazy_type_alias)] +#![allow(incomplete_features)] + +type A<'a> = (); +//~^ ERROR lifetime parameter `'a` is never used +//~| HELP consider removing `'a` + +type B = (); +//~^ ERROR type parameter `T` is never used +//~| HELP consider removing `T` +//~| HELP if you intended `T` to be a const parameter + +// Check that we don't emit the const param help message here: +type C = (); +//~^ ERROR type parameter `T` is never used +//~| HELP consider removing `T` + +fn main() {} diff --git a/tests/ui/lazy-type-alias/unused-generic-parameters.stderr b/tests/ui/lazy-type-alias/unused-generic-parameters.stderr new file mode 100644 index 0000000000000..484e21b0a03f9 --- /dev/null +++ b/tests/ui/lazy-type-alias/unused-generic-parameters.stderr @@ -0,0 +1,28 @@ +error[E0392]: lifetime parameter `'a` is never used + --> $DIR/unused-generic-parameters.rs:8:8 + | +LL | type A<'a> = (); + | ^^ unused lifetime parameter + | + = help: consider removing `'a` or referring to it in the body of the type alias + +error[E0392]: type parameter `T` is never used + --> $DIR/unused-generic-parameters.rs:12:8 + | +LL | type B = (); + | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead + +error[E0392]: type parameter `T` is never used + --> $DIR/unused-generic-parameters.rs:18:8 + | +LL | type C = (); + | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0392`. diff --git a/tests/ui/lifetimes/issue-64173-unused-lifetimes.stderr b/tests/ui/lifetimes/issue-64173-unused-lifetimes.stderr index ec4aea623911a..534ba933ba5d0 100644 --- a/tests/ui/lifetimes/issue-64173-unused-lifetimes.stderr +++ b/tests/ui/lifetimes/issue-64173-unused-lifetimes.stderr @@ -13,19 +13,19 @@ error: generic `Self` types are currently not permitted in anonymous constants LL | array: [(); size_of::<&Self>()], | ^^^^ -error[E0392]: parameter `'s` is never used +error[E0392]: lifetime parameter `'s` is never used --> $DIR/issue-64173-unused-lifetimes.rs:3:12 | LL | struct Foo<'s> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'s`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/issue-64173-unused-lifetimes.rs:15:12 | LL | struct Bar<'a> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/parser/item-free-type-bounds-semantic-fail.rs b/tests/ui/parser/item-free-type-bounds-semantic-fail.rs index 9db4111fbabd9..062b51e597845 100644 --- a/tests/ui/parser/item-free-type-bounds-semantic-fail.rs +++ b/tests/ui/parser/item-free-type-bounds-semantic-fail.rs @@ -13,8 +13,8 @@ fn semantics() { //~| ERROR free type alias without body type E<_T>: Ord = u8; //~^ ERROR bounds on `type`s in this context have no effect - //~| ERROR type parameter `_T` is unused + //~| ERROR type parameter `_T` is never used type F<_T>: Ord where 'static: 'static = u8; //~^ ERROR bounds on `type`s in this context have no effect - //~| ERROR type parameter `_T` is unused + //~| ERROR type parameter `_T` is never used } diff --git a/tests/ui/parser/item-free-type-bounds-semantic-fail.stderr b/tests/ui/parser/item-free-type-bounds-semantic-fail.stderr index 1b086512891f2..1077c10392888 100644 --- a/tests/ui/parser/item-free-type-bounds-semantic-fail.stderr +++ b/tests/ui/parser/item-free-type-bounds-semantic-fail.stderr @@ -50,17 +50,23 @@ error: bounds on `type`s in this context have no effect LL | type F<_T>: Ord where 'static: 'static = u8; | ^^^ -error[E0091]: type parameter `_T` is unused +error[E0091]: type parameter `_T` is never used --> $DIR/item-free-type-bounds-semantic-fail.rs:14:12 | LL | type E<_T>: Ord = u8; | ^^ unused type parameter + | + = help: consider removing `_T` or referring to it in the body of the type alias + = help: if you intended `_T` to be a const parameter, use `const _T: /* Type */` instead -error[E0091]: type parameter `_T` is unused +error[E0091]: type parameter `_T` is never used --> $DIR/item-free-type-bounds-semantic-fail.rs:17:12 | LL | type F<_T>: Ord where 'static: 'static = u8; | ^^ unused type parameter + | + = help: consider removing `_T` or referring to it in the body of the type alias + = help: if you intended `_T` to be a const parameter, use `const _T: /* Type */` instead error: aborting due to 10 previous errors diff --git a/tests/ui/regions/region-bounds-on-objects-and-type-parameters.stderr b/tests/ui/regions/region-bounds-on-objects-and-type-parameters.stderr index 2ec2ca49b1142..b15d2affeea37 100644 --- a/tests/ui/regions/region-bounds-on-objects-and-type-parameters.stderr +++ b/tests/ui/regions/region-bounds-on-objects-and-type-parameters.stderr @@ -21,11 +21,11 @@ note: but lifetime parameter must outlive the lifetime `'a` as defined here LL | struct Foo<'a,'b,'c> { | ^^ -error[E0392]: parameter `'c` is never used +error[E0392]: lifetime parameter `'c` is never used --> $DIR/region-bounds-on-objects-and-type-parameters.rs:11:18 | LL | struct Foo<'a,'b,'c> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'c`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-invalid-places.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-invalid-places.stderr index d57f5702a6382..92a9c347a075e 100644 --- a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-invalid-places.stderr +++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-invalid-places.stderr @@ -272,11 +272,11 @@ LL | type Type = (); = help: add `#![feature(inherent_associated_types)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/tilde-const-invalid-places.rs:11:19 | LL | struct UnitStruct; - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/self/self_type_keyword.stderr b/tests/ui/self/self_type_keyword.stderr index fed853a7e1fd8..4909a9cdc7f5c 100644 --- a/tests/ui/self/self_type_keyword.stderr +++ b/tests/ui/self/self_type_keyword.stderr @@ -72,11 +72,11 @@ note: unit struct `foo::Self` exists but is inaccessible LL | struct Self; | ^^^^^^^^^^^^ not accessible -error[E0392]: parameter `'Self` is never used +error[E0392]: lifetime parameter `'Self` is never used --> $DIR/self_type_keyword.rs:6:12 | LL | struct Bar<'Self>; - | ^^^^^ unused parameter + | ^^^^^ unused lifetime parameter | = help: consider removing `'Self`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/tag-type-args.stderr b/tests/ui/tag-type-args.stderr index 80ffd3a2f0500..a1136f61cc52f 100644 --- a/tests/ui/tag-type-args.stderr +++ b/tests/ui/tag-type-args.stderr @@ -14,14 +14,14 @@ help: add missing generic argument LL | fn foo(c: Quux) { assert!((false)); } | +++ -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/tag-type-args.rs:1:11 | LL | enum Quux { Bar } - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 2 previous errors diff --git a/tests/ui/variance/variance-regions-unused-direct.stderr b/tests/ui/variance/variance-regions-unused-direct.stderr index 1a600f5b0580f..4dc2af6ce2cc8 100644 --- a/tests/ui/variance/variance-regions-unused-direct.stderr +++ b/tests/ui/variance/variance-regions-unused-direct.stderr @@ -1,16 +1,16 @@ -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-regions-unused-direct.rs:5:18 | LL | struct Bivariant<'a>; - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `'d` is never used +error[E0392]: lifetime parameter `'d` is never used --> $DIR/variance-regions-unused-direct.rs:7:19 | LL | struct Struct<'a, 'd> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'d`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/variance/variance-regions-unused-indirect.stderr b/tests/ui/variance/variance-regions-unused-indirect.stderr index 14fdd849294b1..ec4d480baab78 100644 --- a/tests/ui/variance/variance-regions-unused-indirect.stderr +++ b/tests/ui/variance/variance-regions-unused-indirect.stderr @@ -21,19 +21,19 @@ LL | enum Bar<'a> { LL ~ Bar1(Box>) | -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-regions-unused-indirect.rs:3:10 | LL | enum Foo<'a> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-regions-unused-indirect.rs:8:10 | LL | enum Bar<'a> { - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/variance/variance-unused-region-param.stderr b/tests/ui/variance/variance-unused-region-param.stderr index 7c7ec40ba35c3..b9c08bd43c454 100644 --- a/tests/ui/variance/variance-unused-region-param.stderr +++ b/tests/ui/variance/variance-unused-region-param.stderr @@ -1,16 +1,16 @@ -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-unused-region-param.rs:3:19 | LL | struct SomeStruct<'a> { x: u32 } - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `'a` is never used +error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-unused-region-param.rs:4:15 | LL | enum SomeEnum<'a> { Nothing } - | ^^ unused parameter + | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` diff --git a/tests/ui/variance/variance-unused-type-param.stderr b/tests/ui/variance/variance-unused-type-param.stderr index e612da118f058..3011b7bd18fa7 100644 --- a/tests/ui/variance/variance-unused-type-param.stderr +++ b/tests/ui/variance/variance-unused-type-param.stderr @@ -1,51 +1,51 @@ -error[E0392]: parameter `A` is never used +error[E0392]: type parameter `A` is never used --> $DIR/variance-unused-type-param.rs:6:19 | LL | struct SomeStruct { x: u32 } - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `A`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `A` to be a const parameter, use `const A: usize` instead + = help: if you intended `A` to be a const parameter, use `const A: /* Type */` instead -error[E0392]: parameter `A` is never used +error[E0392]: type parameter `A` is never used --> $DIR/variance-unused-type-param.rs:9:15 | LL | enum SomeEnum { Nothing } - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `A`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `A` to be a const parameter, use `const A: usize` instead + = help: if you intended `A` to be a const parameter, use `const A: /* Type */` instead -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/variance-unused-type-param.rs:13:15 | LL | enum ListCell { - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` - = help: if you intended `T` to be a const parameter, use `const T: usize` instead + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/variance-unused-type-param.rs:19:19 | LL | struct WithBounds {} - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/variance-unused-type-param.rs:22:24 | LL | struct WithWhereBounds where T: Sized {} - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` -error[E0392]: parameter `T` is never used +error[E0392]: type parameter `T` is never used --> $DIR/variance-unused-type-param.rs:25:27 | LL | struct WithOutlivesBounds {} - | ^ unused parameter + | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`