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Clearer error diagnostic on type mismatch within a range #67214

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Clearer error diagnostic on type mismatch within a range #67214

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481bc0e
clearer error diagnostic on type mismatch within a range
kevgrasso Nov 15, 2019
3194585
tests updated to match
kevgrasso Dec 10, 2019
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46 changes: 30 additions & 16 deletions src/librustc/infer/error_reporting/mod.rs
View file
Original file line number Diff line number Diff line change
@@ -55,9 +55,8 @@ use crate::hir::Node;
use crate::infer::{self, SuppressRegionErrors};
use crate::infer::opaque_types;
use crate::middle::region;
use crate::traits::{
IfExpressionCause, MatchExpressionArmCause, ObligationCause, ObligationCauseCode,
};
use crate::traits::{ObligationCause, ObligationCauseCode};
use crate::traits::{IfExpressionCause, PatternGuardCause, MatchExpressionArmCause};
use crate::ty::error::TypeError;
use crate::ty::{self, subst::{Subst, SubstsRef}, Region, Ty, TyCtxt, TypeFoldable};

@@ -607,22 +606,32 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
exp_found: Option<ty::error::ExpectedFound<Ty<'tcx>>>,
) {
match cause.code {
ObligationCauseCode::MatchExpressionArmPattern { span, ty } => {
if ty.is_suggestable() { // don't show type `_`
err.span_label(span, format!("this match expression has type `{}`", ty));
}
if let Some(ty::error::ExpectedFound { found, .. }) = exp_found {
if ty.is_box() && ty.boxed_ty() == found {
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
"consider dereferencing the boxed value",
format!("*{}", snippet),
Applicability::MachineApplicable,
);
ObligationCauseCode::PatternGuard(box PatternGuardCause {
match_expr_discrim, other_range_expr
}) => {
if let Some((span, ty)) = match_expr_discrim {
if ty.is_suggestable() { // don't show type `_`
err.span_label(
span,
format!("this match expression requires type `{}`", ty)
);
}
if let Some(ty::error::ExpectedFound { found, .. }) = exp_found {
if ty.is_box() && ty.boxed_ty() == found {
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
"consider dereferencing the boxed value",
format!("*{}", snippet),
Applicability::MachineApplicable,
);
}
}
}
}
if let Some((span, ty)) = other_range_expr {
err.span_label(span, format!("other endpoint has type `{}`", ty));
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I feel like "this endpoint has type will lend itself to less confusion in the output.

}
}
ObligationCauseCode::MatchExpressionArm(box MatchExpressionArmCause {
source,
@@ -1338,6 +1347,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
}
_ => (false, None),
};
debug!("note_type_err: values={:?}", values);
let vals = match self.values_str(&values) {
Some((expected, found)) => Some((expected, found)),
None => {
@@ -1365,6 +1375,10 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
};

if let Some((expected, found)) = expected_found {
debug!(
"note_type_err: exp_found={:?}, expected={:?} found={:?}",
exp_found, expected, found
);
let expected_label = exp_found.map_or("type".into(), |ef| ef.expected.prefix_string());
let found_label = exp_found.map_or("type".into(), |ef| ef.found.prefix_string());
match (&terr, expected == found) {
2 changes: 1 addition & 1 deletion src/librustc/traits/error_reporting.rs
View file
Original file line number Diff line number Diff line change
@@ -2273,7 +2273,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
match *cause_code {
ObligationCauseCode::ExprAssignable |
ObligationCauseCode::MatchExpressionArm { .. } |
ObligationCauseCode::MatchExpressionArmPattern { .. } |
ObligationCauseCode::PatternGuard { .. } |
ObligationCauseCode::IfExpression { .. } |
ObligationCauseCode::IfExpressionWithNoElse |
ObligationCauseCode::MainFunctionType |
10 changes: 8 additions & 2 deletions src/librustc/traits/mod.rs
View file
Original file line number Diff line number Diff line change
@@ -237,8 +237,8 @@ pub enum ObligationCauseCode<'tcx> {
/// Computing common supertype in the arms of a match expression
MatchExpressionArm(Box<MatchExpressionArmCause<'tcx>>),

/// Computing common supertype in the pattern guard for the arms of a match expression
MatchExpressionArmPattern { span: Span, ty: Ty<'tcx> },
/// Computing common supertype in a pattern guard
PatternGuard(Box<PatternGuardCause<'tcx>>),
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PatternGuard feels misleading as the usage in demand_eqtype_pat_diag is about patterns. (There's also no such thing as a pattern guard. Only arms have guards.)


/// Constants in patterns must have `Structural` type.
ConstPatternStructural,
@@ -299,6 +299,12 @@ pub struct MatchExpressionArmCause<'tcx> {
pub discrim_hir_id: hir::HirId,
}

#[derive(Clone, Debug, PartialEq, Eq, Hash)]
pub struct PatternGuardCause<'tcx> {
pub match_expr_discrim: Option<(Span, Ty<'tcx>)>,
pub other_range_expr: Option<(Span, Ty<'tcx>)>,
}

#[derive(Clone, Debug, PartialEq, Eq, Hash)]
pub struct IfExpressionCause {
pub then: Span,
9 changes: 6 additions & 3 deletions src/librustc/traits/structural_impls.rs
View file
Original file line number Diff line number Diff line change
@@ -532,9 +532,12 @@ impl<'a, 'tcx> Lift<'tcx> for traits::ObligationCauseCode<'a> {
})
})
}
super::MatchExpressionArmPattern { span, ty } => {
tcx.lift(&ty).map(|ty| super::MatchExpressionArmPattern { span, ty })
}
super::PatternGuard(box super::PatternGuardCause {
match_expr_discrim, other_range_expr,
}) => Some(super::PatternGuard(box super::PatternGuardCause {
match_expr_discrim: tcx.lift(&match_expr_discrim)?,
other_range_expr: tcx.lift(&other_range_expr)?,
})),
super::IfExpression(box super::IfExpressionCause { then, outer, semicolon }) => {
Some(super::IfExpression(box super::IfExpressionCause {
then,
11 changes: 2 additions & 9 deletions src/librustc_typeck/check/demand.rs
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
use crate::check::FnCtxt;
use rustc::infer::InferOk;
use rustc::traits::{self, ObligationCause, ObligationCauseCode};
use rustc::traits::{self, ObligationCause};

use syntax::symbol::sym;
use syntax::util::parser::PREC_POSTFIX;
@@ -88,14 +88,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
actual: Ty<'tcx>,
match_expr_span: Option<Span>,
) -> Option<DiagnosticBuilder<'tcx>> {
let cause = if let Some(span) = match_expr_span {
self.cause(
cause_span,
ObligationCauseCode::MatchExpressionArmPattern { span, ty: expected },
)
} else {
self.misc(cause_span)
};
let cause = self.pat_guard_cause(None, cause_span, expected, match_expr_span);
self.demand_eqtype_with_origin(&cause, expected, actual)
}

21 changes: 20 additions & 1 deletion src/librustc_typeck/check/mod.rs
View file
Original file line number Diff line number Diff line change
@@ -106,7 +106,7 @@ use rustc::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
use rustc::middle::region;
use rustc::mir::interpret::{ConstValue, GlobalId};
use rustc::traits::{self, ObligationCause, ObligationCauseCode, TraitEngine};
use rustc::traits::{self, ObligationCause, ObligationCauseCode, PatternGuardCause, TraitEngine};
use rustc::ty::{
self, AdtKind, CanonicalUserType, Ty, TyCtxt, Const, GenericParamDefKind,
ToPolyTraitRef, ToPredicate, RegionKind, UserType
@@ -2738,6 +2738,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
self.cause(span, ObligationCauseCode::MiscObligation)
}

pub fn pat_guard_cause(
&self,
other_range_expr: Option<(Span, Ty<'tcx>)>,
cause_span: Span,
expected: Ty<'tcx>,
match_expr_discrim: Option<Span>
) -> ObligationCause<'tcx> {
match (other_range_expr, match_expr_discrim) {
(Some(_), _) | (_, Some(_)) => self.cause(
cause_span, // error primary span
ObligationCauseCode::PatternGuard(box PatternGuardCause {
match_expr_discrim: match_expr_discrim.map(|span| (span, expected)),
other_range_expr
})
),
_ => self.misc(cause_span)
}
}

/// Resolves type and const variables in `ty` if possible. Unlike the infcx
/// version (resolve_vars_if_possible), this version will
/// also select obligations if it seems useful, in an effort
79 changes: 70 additions & 9 deletions src/librustc_typeck/check/pat.rs
View file
Original file line number Diff line number Diff line change
@@ -355,8 +355,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
expected: Ty<'tcx>,
discrim_span: Option<Span>,
) -> Option<Ty<'tcx>> {
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I feel that if you change the return type to Result<Ty<'tcx>, DiagnosticBuilder<'tcx>> it will let you clean up a few lines below. Just make sure that in the single check_pat_range caller you emit the error.

debug!("check_pat_range(begin={:?}, end={:?}, discrim_span={:?})",
begin, end, discrim_span
);

let lhs_ty = self.check_expr(begin);
let rhs_ty = self.check_expr(end);
debug!("check_pat_range: expected={:?}, expected.kind={:?}, lhs_ty={:?}, rhs_ty={:?}",
expected, expected.kind, lhs_ty, rhs_ty
);

// Check that both end-points are of numeric or char type.
let numeric_or_char = |ty: Ty<'_>| {
@@ -371,17 +378,71 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
self.emit_err_pat_range(
span, begin.span, end.span, lhs_fail, rhs_fail, lhs_ty, rhs_ty
);
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You'll have to change emit_err_pat_range to return the error instead of emitting it.

All of this then becomes

            return self.emit_err_pat_range(
                span, begin.span, end.span, lhs_fail, rhs_fail, lhs_ty, rhs_ty
                span, begin.span, end.span, lhs_fail, rhs_fail, lhs_ty, rhs_ty
            );

which lets you have the else clause implicit, removing one indentation level.

return None;
}

// Now that we know the types can be unified we find the unified type and use
// it to type the entire expression.
let common_type = self.resolve_vars_if_possible(&lhs_ty);
None
} else {
use rustc::traits::PredicateObligations;
use infer::InferOk;

let at_cause_eq = |
expect_ty: Ty<'tcx>, actual_type: Ty<'tcx>, cause_span: Span,
other_expr: Option<(Span, Ty<'tcx>)>
| {
if !actual_type.references_error() {
let other_expr = other_expr.filter(|(_, ty)| !ty.references_error());
let cause = self.pat_guard_cause(
other_expr, cause_span, expected, discrim_span
);

let result = self.at(&cause, self.param_env).eq(expect_ty, actual_type);
result.map_err(|terr| (cause, terr))
} else {
Ok(InferOk {obligations: PredicateObligations::new(), value: ()})
}
};

// test if sides both sides of range have the compatible types
let lhs_result = at_cause_eq(expected, lhs_ty, begin.span, Some((end.span, rhs_ty)));
let rhs_result = at_cause_eq(expected, rhs_ty, end.span, Some((begin.span, lhs_ty)));

let joined_result = match (lhs_result, rhs_result) {
// full success, move forwards
(
Ok(InferOk { obligations: lhs_obligation, value: () }),
Ok(InferOk { obligations: rhs_obligation, value: () })
) => {
self.register_predicates(lhs_obligation);
self.register_predicates(rhs_obligation);

// Now that we know the types can be unified we find the unified type and use
// it to type the entire expression.
Ok(self.resolve_vars_if_possible(&lhs_ty))
},
// only lhs is wrong
(Err((cause, terr)), Ok(_)) =>
Err(self.report_mismatched_types(&cause, expected, lhs_ty, terr)),
// only rhs is wrong
(Ok(_), Err((cause, terr))) =>
Err(self.report_mismatched_types(&cause, expected, rhs_ty, terr)),
// both sides are wrong
(Err(_), Err((rhs_cause, terr))) => {
if let Ok(_) = at_cause_eq(lhs_ty, rhs_ty, Span::default(), None) {
let cause = self.pat_guard_cause(None, span, expected, discrim_span);
Err(self.report_mismatched_types(&cause, expected, rhs_ty, terr))
} else {
Err(self.report_mismatched_types(&rhs_cause, expected, rhs_ty, terr))
}
}
};

// Subtyping doesn't matter here, as the value is some kind of scalar.
self.demand_eqtype_pat(span, expected, lhs_ty, discrim_span);
self.demand_eqtype_pat(span, expected, rhs_ty, discrim_span);
Some(common_type)
match joined_result {
Ok(common_type) => Some(common_type),
Err(mut err) => {
err.emit();
None
}
}
}
Comment on lines +384 to +445
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I'm not happy about the amount of special casing, rawness, and the fragility of this type checking logic.
Looking right now to see if there's a less complicated way to get near the same results.

}

fn emit_err_pat_range(
2 changes: 1 addition & 1 deletion src/test/ui/block-result/issue-13624.stderr
View file
Original file line number Diff line number Diff line change
@@ -10,7 +10,7 @@ error[E0308]: mismatched types
--> $DIR/issue-13624.rs:20:9
|
LL | match enum_struct_variant {
| ------------------- this match expression has type `()`
| ------------------- this match expression requires type `()`
LL | a::Enum::EnumStructVariant { x, y, z } => {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found enum `a::Enum`

8 changes: 5 additions & 3 deletions src/test/ui/error-codes/E0308-4.stderr
View file
Original file line number Diff line number Diff line change
@@ -1,10 +1,12 @@
error[E0308]: mismatched types
--> $DIR/E0308-4.rs:4:9
--> $DIR/E0308-4.rs:4:15
|
LL | match x {
| - this match expression has type `u8`
| - this match expression requires type `u8`
LL | 0u8..=3i8 => (),
| ^^^^^^^^^ expected `u8`, found `i8`
| --- ^^^ expected `u8`, found `i8`
| |
| other endpoint has type `u8`

error: aborting due to previous error

4 changes: 2 additions & 2 deletions src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision.stderr
View file
Original file line number Diff line number Diff line change
@@ -8,9 +8,9 @@ error[E0308]: mismatched types
--> $DIR/exclusive_range_pattern_syntax_collision.rs:5:13
|
LL | match [5..4, 99..105, 43..44] {
| ----------------------- this match expression has type `std::ops::Range<{integer}>`
| ----------------------- this match expression requires type `std::ops::Range<{integer}>`
LL | [_, 99.., _] => {},
| ^^^^ expected struct `std::ops::Range`, found integer
| ^^ expected struct `std::ops::Range`, found integer
|
= note: expected struct `std::ops::Range<{integer}>`
found type `{integer}`
4 changes: 2 additions & 2 deletions src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision2.stderr
View file
Original file line number Diff line number Diff line change
@@ -14,9 +14,9 @@ error[E0308]: mismatched types
--> $DIR/exclusive_range_pattern_syntax_collision2.rs:5:13
|
LL | match [5..4, 99..105, 43..44] {
| ----------------------- this match expression has type `std::ops::Range<{integer}>`
| ----------------------- this match expression requires type `std::ops::Range<{integer}>`
LL | [_, 99..] => {},
| ^^^^ expected struct `std::ops::Range`, found integer
| ^^ expected struct `std::ops::Range`, found integer
|
= note: expected struct `std::ops::Range<{integer}>`
found type `{integer}`
8 changes: 4 additions & 4 deletions src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision3.stderr
View file
Original file line number Diff line number Diff line change
@@ -5,12 +5,12 @@ LL | [..9, 99..100, _] => {},
| ^^^ help: try using the minimum value for the type: `MIN..9`

error[E0308]: mismatched types
--> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:10
--> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:12
|
LL | match [5..4, 99..105, 43..44] {
| ----------------------- this match expression has type `std::ops::Range<{integer}>`
| ----------------------- this match expression requires type `std::ops::Range<{integer}>`
LL | [..9, 99..100, _] => {},
| ^^^ expected struct `std::ops::Range`, found integer
| ^ expected struct `std::ops::Range`, found integer
|
= note: expected struct `std::ops::Range<{integer}>`
found type `{integer}`
@@ -19,7 +19,7 @@ error[E0308]: mismatched types
--> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:15
|
LL | match [5..4, 99..105, 43..44] {
| ----------------------- this match expression has type `std::ops::Range<{integer}>`
| ----------------------- this match expression requires type `std::ops::Range<{integer}>`
LL | [..9, 99..100, _] => {},
| ^^^^^^^ expected struct `std::ops::Range`, found integer
|
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-11844.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-11844.rs:6:9
|
LL | match a {
| - this match expression has type `std::option::Option<std::boxed::Box<{integer}>>`
| - this match expression requires type `std::option::Option<std::boxed::Box<{integer}>>`
LL | Ok(a) =>
| ^^^^^ expected enum `std::option::Option`, found enum `std::result::Result`
|
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-12552.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-12552.rs:6:5
|
LL | match t {
| - this match expression has type `std::result::Result<_, {integer}>`
| - this match expression requires type `std::result::Result<_, {integer}>`
LL | Some(k) => match k {
| ^^^^^^^ expected enum `std::result::Result`, found enum `std::option::Option`
|
4 changes: 2 additions & 2 deletions src/test/ui/issues/issue-13466.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-13466.rs:8:9
|
LL | let _x: usize = match Some(1) {
| ------- this match expression has type `std::option::Option<{integer}>`
| ------- this match expression requires type `std::option::Option<{integer}>`
LL | Ok(u) => u,
| ^^^^^ expected enum `std::option::Option`, found enum `std::result::Result`
|
@@ -13,7 +13,7 @@ error[E0308]: mismatched types
--> $DIR/issue-13466.rs:14:9
|
LL | let _x: usize = match Some(1) {
| ------- this match expression has type `std::option::Option<{integer}>`
| ------- this match expression requires type `std::option::Option<{integer}>`
...
LL | Err(e) => panic!(e)
| ^^^^^^ expected enum `std::option::Option`, found enum `std::result::Result`
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-15896.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-15896.rs:11:11
|
LL | let u = match e {
| - this match expression has type `main::R`
| - this match expression requires type `main::R`
LL | E::B(
LL | Tau{t: x},
| ^^^^^^^^^ expected enum `main::R`, found struct `main::Tau`
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-16401.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-16401.rs:8:9
|
LL | match () {
| -- this match expression has type `()`
| -- this match expression requires type `()`
LL | Slice { data: data, len: len } => (),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found struct `Slice`
|
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-3680.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-3680.rs:3:9
|
LL | match None {
| ---- this match expression has type `std::option::Option<_>`
| ---- this match expression requires type `std::option::Option<_>`
LL | Err(_) => ()
| ^^^^^^ expected enum `std::option::Option`, found enum `std::result::Result`
|
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-5100.stderr
View file
Original file line number Diff line number Diff line change
@@ -29,7 +29,7 @@ error[E0308]: mismatched types
--> $DIR/issue-5100.rs:33:9
|
LL | match (true, false) {
| ------------- this match expression has type `(bool, bool)`
| ------------- this match expression requires type `(bool, bool)`
LL | box (true, false) => ()
| ^^^^^^^^^^^^^^^^^ expected tuple, found struct `std::boxed::Box`
|
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-5358-1.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-5358-1.rs:6:9
|
LL | match S(Either::Left(5)) {
| ------------------ this match expression has type `S`
| ------------------ this match expression requires type `S`
LL | Either::Right(_) => {}
| ^^^^^^^^^^^^^^^^ expected struct `S`, found enum `Either`
|
4 changes: 2 additions & 2 deletions src/test/ui/issues/issue-57741-1.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-57741-1.rs:14:9
|
LL | let y = match x {
| - this match expression has type `std::boxed::Box<u32>`
| - this match expression requires type `std::boxed::Box<u32>`
LL | S::A { a } | S::B { b: a } => a,
| ^^^^^^^^^^ expected struct `std::boxed::Box`, found enum `S`
|
@@ -13,7 +13,7 @@ error[E0308]: mismatched types
--> $DIR/issue-57741-1.rs:14:22
|
LL | let y = match x {
| - this match expression has type `std::boxed::Box<u32>`
| - this match expression requires type `std::boxed::Box<u32>`
LL | S::A { a } | S::B { b: a } => a,
| ^^^^^^^^^^^^^ expected struct `std::boxed::Box`, found enum `S`
|
8 changes: 4 additions & 4 deletions src/test/ui/issues/issue-57741.stderr
View file
Original file line number Diff line number Diff line change
@@ -4,7 +4,7 @@ error[E0308]: mismatched types
LL | let y = match x {
| -
| |
| this match expression has type `std::boxed::Box<T>`
| this match expression requires type `std::boxed::Box<T>`
| help: consider dereferencing the boxed value: `*x`
LL | T::A(a) | T::B(a) => a,
| ^^^^^^^ expected struct `std::boxed::Box`, found enum `T`
@@ -18,7 +18,7 @@ error[E0308]: mismatched types
LL | let y = match x {
| -
| |
| this match expression has type `std::boxed::Box<T>`
| this match expression requires type `std::boxed::Box<T>`
| help: consider dereferencing the boxed value: `*x`
LL | T::A(a) | T::B(a) => a,
| ^^^^^^^ expected struct `std::boxed::Box`, found enum `T`
@@ -32,7 +32,7 @@ error[E0308]: mismatched types
LL | let y = match x {
| -
| |
| this match expression has type `std::boxed::Box<S>`
| this match expression requires type `std::boxed::Box<S>`
| help: consider dereferencing the boxed value: `*x`
LL | S::A { a } | S::B { b: a } => a,
| ^^^^^^^^^^ expected struct `std::boxed::Box`, found enum `S`
@@ -46,7 +46,7 @@ error[E0308]: mismatched types
LL | let y = match x {
| -
| |
| this match expression has type `std::boxed::Box<S>`
| this match expression requires type `std::boxed::Box<S>`
| help: consider dereferencing the boxed value: `*x`
LL | S::A { a } | S::B { b: a } => a,
| ^^^^^^^^^^^^^ expected struct `std::boxed::Box`, found enum `S`
2 changes: 1 addition & 1 deletion src/test/ui/issues/issue-7092.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/issue-7092.rs:6:9
|
LL | match x {
| - this match expression has type `Whatever`
| - this match expression requires type `Whatever`
LL | Some(field) =>
| ^^^^^^^^^^^ expected enum `Whatever`, found enum `std::option::Option`
|
4 changes: 3 additions & 1 deletion src/test/ui/match/match-range-fail.stderr
View file
Original file line number Diff line number Diff line change
@@ -28,7 +28,9 @@ error[E0308]: mismatched types
--> $DIR/match-range-fail.rs:18:9
|
LL | 'c' ..= 100 => { }
| ^^^^^^^^^^^ expected integer, found `char`
| ^^^ --- other endpoint has type `{integer}`
| |
| expected integer, found `char`

error: aborting due to 4 previous errors

2 changes: 1 addition & 1 deletion src/test/ui/match/match-struct.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/match-struct.rs:6:9
|
LL | match (S { a: 1 }) {
| ------------ this match expression has type `S`
| ------------ this match expression requires type `S`
LL | E::C(_) => (),
| ^^^^^^^ expected struct `S`, found enum `E`

2 changes: 1 addition & 1 deletion src/test/ui/match/match-tag-unary.stderr
View file
Original file line number Diff line number Diff line change
@@ -4,7 +4,7 @@ error[E0308]: mismatched types
LL | fn main() { let x: A = A::A(0); match x { B::B(y) => { } } }
| - ^^^^^^^ expected enum `A`, found enum `B`
| |
| this match expression has type `A`
| this match expression requires type `A`

error: aborting due to previous error

4 changes: 2 additions & 2 deletions src/test/ui/parser/pat-tuple-5.stderr
View file
Original file line number Diff line number Diff line change
@@ -17,9 +17,9 @@ error[E0308]: mismatched types
--> $DIR/pat-tuple-5.rs:5:10
|
LL | match (0, 1) {
| ------ this match expression has type `({integer}, {integer})`
| ------ this match expression requires type `({integer}, {integer})`
LL | (PAT ..) => {}
| ^^^^^^ expected tuple, found `u8`
| ^^^ expected tuple, found `u8`
|
= note: expected tuple `({integer}, {integer})`
found type `u8`
48 changes: 30 additions & 18 deletions src/test/ui/parser/recover-range-pats.stderr
View file
Original file line number Diff line number Diff line change
@@ -417,13 +417,17 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:21:12
|
LL | if let .0..Y = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ - other endpoint has type `u8`
| |
| expected integer, found floating-point number

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:23:12
--> $DIR/recover-range-pats.rs:23:16
|
LL | if let X.. .0 = 0 {}
| ^^^^^^ expected integer, found floating-point number
| - ^^ expected integer, found floating-point number
| |
| other endpoint has type `u8`

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:32:12
@@ -445,13 +449,17 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:34:12
|
LL | if let .0..=Y = 0 {}
| ^^^^^^ expected integer, found floating-point number
| ^^ - other endpoint has type `u8`
| |
| expected integer, found floating-point number

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:36:12
--> $DIR/recover-range-pats.rs:36:16
|
LL | if let X..=.0 = 0 {}
| ^^^^^^ expected integer, found floating-point number
| - ^^ expected integer, found floating-point number
| |
| other endpoint has type `u8`

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:45:12
@@ -473,13 +481,17 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:49:12
|
LL | if let .0...Y = 0 {}
| ^^^^^^ expected integer, found floating-point number
| ^^ - other endpoint has type `u8`
| |
| expected integer, found floating-point number

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:52:12
--> $DIR/recover-range-pats.rs:52:17
|
LL | if let X... .0 = 0 {}
| ^^^^^^^ expected integer, found floating-point number
| - ^^ expected integer, found floating-point number
| |
| other endpoint has type `u8`

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:60:12
@@ -491,7 +503,7 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:62:12
|
LL | if let .0.. = 0 {}
| ^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:70:12
@@ -503,7 +515,7 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:72:12
|
LL | if let .0..= = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:82:12
@@ -515,7 +527,7 @@ error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:85:12
|
LL | if let .0... = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:94:14
@@ -524,10 +536,10 @@ LL | if let ..true = 0 {}
| ^^^^ this is of type `bool` but it should be `char` or numeric

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:96:12
--> $DIR/recover-range-pats.rs:96:15
|
LL | if let .. .0 = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:104:15
@@ -536,10 +548,10 @@ LL | if let ..=true = 0 {}
| ^^^^ this is of type `bool` but it should be `char` or numeric

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:106:12
--> $DIR/recover-range-pats.rs:106:15
|
LL | if let ..=.0 = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error[E0029]: only char and numeric types are allowed in range patterns
--> $DIR/recover-range-pats.rs:116:15
@@ -548,10 +560,10 @@ LL | if let ...true = 0 {}
| ^^^^ this is of type `bool` but it should be `char` or numeric

error[E0308]: mismatched types
--> $DIR/recover-range-pats.rs:119:12
--> $DIR/recover-range-pats.rs:119:15
|
LL | if let ....3 = 0 {}
| ^^^^^ expected integer, found floating-point number
| ^^ expected integer, found floating-point number

error: aborting due to 85 previous errors

2 changes: 1 addition & 1 deletion src/test/ui/pattern/pattern-error-continue.stderr
View file
Original file line number Diff line number Diff line change
@@ -28,7 +28,7 @@ error[E0308]: mismatched types
--> $DIR/pattern-error-continue.rs:22:9
|
LL | match 'c' {
| --- this match expression has type `char`
| --- this match expression requires type `char`
LL | S { .. } => (),
| ^^^^^^^^ expected `char`, found struct `S`

2 changes: 1 addition & 1 deletion src/test/ui/pattern/pattern-tyvar.stderr
View file
Original file line number Diff line number Diff line change
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
--> $DIR/pattern-tyvar.rs:5:18
|
LL | match t {
| - this match expression has type `std::option::Option<std::vec::Vec<isize>>`
| - this match expression requires type `std::option::Option<std::vec::Vec<isize>>`
LL | Bar::T1(_, Some::<isize>(x)) => {
| ^^^^^^^^^^^^^^^^ expected struct `std::vec::Vec`, found `isize`
|
14 changes: 7 additions & 7 deletions src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
View file
Original file line number Diff line number Diff line change
@@ -630,7 +630,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:67:12
|
LL | if let Range { start: _, end: _ } = true..true && false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -650,7 +650,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:71:12
|
LL | if let Range { start: _, end: _ } = true..true || false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -697,7 +697,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:86:12
|
LL | if let Range { start: true, end } = t..&&false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ - this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ - this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -818,7 +818,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:131:15
|
LL | while let Range { start: _, end: _ } = true..true && false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -838,7 +838,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:135:15
|
LL | while let Range { start: _, end: _ } = true..true || false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -885,7 +885,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:150:15
|
LL | while let Range { start: true, end } = t..&&false {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ - this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ - this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
@@ -961,7 +961,7 @@ error[E0308]: mismatched types
--> $DIR/disallowed-positions.rs:198:10
|
LL | (let Range { start: _, end: _ } = true..true || false);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression has type `bool`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ ---- this match expression requires type `bool`
| |
| expected `bool`, found struct `std::ops::Range`
|
6 changes: 3 additions & 3 deletions src/test/ui/structs/structure-constructor-type-mismatch.stderr
View file
Original file line number Diff line number Diff line change
@@ -86,7 +86,7 @@ error[E0308]: mismatched types
--> $DIR/structure-constructor-type-mismatch.rs:54:9
|
LL | match (Point { x: 1, y: 2 }) {
| ---------------------- this match expression has type `Point<{integer}>`
| ---------------------- this match expression requires type `Point<{integer}>`
LL | PointF::<u32> { .. } => {}
| ^^^^^^^^^^^^^^^^^^^^ expected integer, found `f32`
|
@@ -97,7 +97,7 @@ error[E0308]: mismatched types
--> $DIR/structure-constructor-type-mismatch.rs:59:9
|
LL | match (Point { x: 1, y: 2 }) {
| ---------------------- this match expression has type `Point<{integer}>`
| ---------------------- this match expression requires type `Point<{integer}>`
LL | PointF { .. } => {}
| ^^^^^^^^^^^^^ expected integer, found `f32`
|
@@ -108,7 +108,7 @@ error[E0308]: mismatched types
--> $DIR/structure-constructor-type-mismatch.rs:67:9
|
LL | match (Pair { x: 1, y: 2 }) {
| --------------------- this match expression has type `Pair<{integer}, {integer}>`
| --------------------- this match expression requires type `Pair<{integer}, {integer}>`
LL | PairF::<u32> { .. } => {}
| ^^^^^^^^^^^^^^^^^^^ expected integer, found `f32`
|