Rollup merge of #59453 - estebank:recover-tuple-parse, r=petrochenkov

Recover from parse error in tuple syntax

src/test/ui/issues/issue-34334.rs

@@ -1,4 +1,10 @@
 fn main () {
-    let sr: Vec<(u32, _, _) = vec![]; //~ ERROR expected one of `,` or `>`, found `=`
+    let sr: Vec<(u32, _, _) = vec![];
+    //~^ ERROR expected one of `,` or `>`, found `=`
+    //~| ERROR expected value, found struct `Vec`
+    //~| ERROR mismatched types
+    //~| ERROR invalid left-hand side expression
+    //~| ERROR expected expression, found reserved identifier `_`
     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
+    //~^ ERROR no method named `iter` found for type `()` in the current scope
 }

src/test/ui/issues/issue-34334.stderr

@@ -1,10 +1,47 @@
+error: expected expression, found reserved identifier `_`
+  --> $DIR/issue-34334.rs:2:23
+   |
+LL |     let sr: Vec<(u32, _, _) = vec![];
+   |                       ^ expected expression
+
 error: expected one of `,` or `>`, found `=`
   --> $DIR/issue-34334.rs:2:29
    |
 LL |     let sr: Vec<(u32, _, _) = vec![];
-   |         --                  ^ expected one of `,` or `>` here
-   |         |
+   |         ---                 ^ expected one of `,` or `>` here
+   |         | |
+   |         | help: use `=` if you meant to assign
    |         while parsing the type for `sr`
 
-error: aborting due to previous error
+error[E0423]: expected value, found struct `Vec`
+  --> $DIR/issue-34334.rs:2:13
+   |
+LL |     let sr: Vec<(u32, _, _) = vec![];
+   |             ^^^ did you mean `Vec { /* fields */ }`?
 
+error[E0308]: mismatched types
+  --> $DIR/issue-34334.rs:2:31
+   |
+LL |     let sr: Vec<(u32, _, _) = vec![];
+   |                               ^^^^^^ expected bool, found struct `std::vec::Vec`
+   |
+   = note: expected type `bool`
+              found type `std::vec::Vec<_>`
+   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
+
+error[E0070]: invalid left-hand side expression
+  --> $DIR/issue-34334.rs:2:13
+   |
+LL |     let sr: Vec<(u32, _, _) = vec![];
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ left-hand of expression not valid
+
+error[E0599]: no method named `iter` found for type `()` in the current scope
+  --> $DIR/issue-34334.rs:8:36
+   |
+LL |     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
+   |                                    ^^^^
+
+error: aborting due to 6 previous errors
+
+Some errors occurred: E0070, E0308, E0423, E0599.
+For more information about an error, try `rustc --explain E0070`.