diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index 7b86791026b41..f58ac9f00e4cc 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -744,8 +744,10 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
} else {
let (closure_span, found) = found_did
.and_then(|did| self.tcx.hir.get_if_local(did))
- .map(|node| self.get_fn_like_arguments(node))
- .unwrap_or((found_span.unwrap(), found));
+ .map(|node| {
+ let (found_span, found) = self.get_fn_like_arguments(node);
+ (Some(found_span), found)
+ }).unwrap_or((found_span, found));
self.report_arg_count_mismatch(span,
closure_span,
@@ -855,7 +857,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
fn report_arg_count_mismatch(
&self,
span: Span,
- found_span: Span,
+ found_span: Option<Span>,
expected_args: Vec<ArgKind>,
found_args: Vec<ArgKind>,
is_closure: bool,
@@ -893,48 +895,51 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
);
err.span_label(span, format!( "expected {} that takes {}", kind, expected_str));
- err.span_label(found_span, format!("takes {}", found_str));
-
- if let &[ArgKind::Tuple(_, ref fields)] = &found_args[..] {
- if fields.len() == expected_args.len() {
- let sugg = fields.iter()
- .map(|(name, _)| name.to_owned())
- .collect::<Vec<String>>().join(", ");
- err.span_suggestion(found_span,
- "change the closure to take multiple arguments instead of \
- a single tuple",
- format!("|{}|", sugg));
+
+ if let Some(found_span) = found_span {
+ err.span_label(found_span, format!("takes {}", found_str));
+
+ if let &[ArgKind::Tuple(_, ref fields)] = &found_args[..] {
+ if fields.len() == expected_args.len() {
+ let sugg = fields.iter()
+ .map(|(name, _)| name.to_owned())
+ .collect::<Vec<String>>().join(", ");
+ err.span_suggestion(found_span,
+ "change the closure to take multiple arguments instead of \
+ a single tuple",
+ format!("|{}|", sugg));
+ }
}
- }
- if let &[ArgKind::Tuple(_, ref fields)] = &expected_args[..] {
- if fields.len() == found_args.len() && is_closure {
- let sugg = format!(
- "|({}){}|",
- found_args.iter()
- .map(|arg| match arg {
- ArgKind::Arg(name, _) => name.to_owned(),
- _ => "_".to_owned(),
- })
- .collect::<Vec<String>>()
- .join(", "),
- // add type annotations if available
- if found_args.iter().any(|arg| match arg {
- ArgKind::Arg(_, ty) => ty != "_",
- _ => false,
- }) {
- format!(": ({})",
- fields.iter()
- .map(|(_, ty)| ty.to_owned())
- .collect::<Vec<String>>()
- .join(", "))
- } else {
- "".to_owned()
- },
- );
- err.span_suggestion(found_span,
- "change the closure to accept a tuple instead of individual \
- arguments",
- sugg);
+ if let &[ArgKind::Tuple(_, ref fields)] = &expected_args[..] {
+ if fields.len() == found_args.len() && is_closure {
+ let sugg = format!(
+ "|({}){}|",
+ found_args.iter()
+ .map(|arg| match arg {
+ ArgKind::Arg(name, _) => name.to_owned(),
+ _ => "_".to_owned(),
+ })
+ .collect::<Vec<String>>()
+ .join(", "),
+ // add type annotations if available
+ if found_args.iter().any(|arg| match arg {
+ ArgKind::Arg(_, ty) => ty != "_",
+ _ => false,
+ }) {
+ format!(": ({})",
+ fields.iter()
+ .map(|(_, ty)| ty.to_owned())
+ .collect::<Vec<String>>()
+ .join(", "))
+ } else {
+ "".to_owned()
+ },
+ );
+ err.span_suggestion(found_span,
+ "change the closure to accept a tuple instead of \
+ individual arguments",
+ sugg);
+ }
}
}
diff --git a/src/test/ui/mismatched_types/closure-arg-count.rs b/src/test/ui/mismatched_types/closure-arg-count.rs
index 96e5201716c71..34232e81cbdee 100644
--- a/src/test/ui/mismatched_types/closure-arg-count.rs
+++ b/src/test/ui/mismatched_types/closure-arg-count.rs
@@ -36,6 +36,9 @@ fn main() {
//~^ ERROR closure is expected to take
let _it = vec![1, 2, 3].into_iter().enumerate().map(qux);
//~^ ERROR function is expected to take
+
+ let _it = vec![1, 2, 3].into_iter().map(usize::checked_add);
+ //~^ ERROR function is expected to take
}
fn foo() {}
diff --git a/src/test/ui/mismatched_types/closure-arg-count.stderr b/src/test/ui/mismatched_types/closure-arg-count.stderr
index be00ee4d74e7e..d2a6d6da814ca 100644
--- a/src/test/ui/mismatched_types/closure-arg-count.stderr
+++ b/src/test/ui/mismatched_types/closure-arg-count.stderr
@@ -90,7 +90,7 @@ error[E0593]: function is expected to take a single 2-tuple as argument, but it
32 | let _it = vec![1, 2, 3].into_iter().enumerate().map(foo);
| ^^^ expected function that takes a single 2-tuple as argument
...
-41 | fn foo() {}
+44 | fn foo() {}
| -------- takes 0 arguments
error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 3 distinct arguments
@@ -107,8 +107,14 @@ error[E0593]: function is expected to take a single 2-tuple as argument, but it
37 | let _it = vec![1, 2, 3].into_iter().enumerate().map(qux);
| ^^^ expected function that takes a single 2-tuple as argument
...
-42 | fn qux(x: usize, y: usize) {}
+45 | fn qux(x: usize, y: usize) {}
| -------------------------- takes 2 distinct arguments
-error: aborting due to 11 previous errors
+error[E0593]: function is expected to take 1 argument, but it takes 2 arguments
+ --> $DIR/closure-arg-count.rs:40:41
+ |
+40 | let _it = vec![1, 2, 3].into_iter().map(usize::checked_add);
+ | ^^^ expected function that takes 1 argument
+
+error: aborting due to 12 previous errors