---

yaml
---
r: 152184
b: refs/heads/try2
c: b64046a
h: refs/heads/master
v: v3

Author: Jakub Wieczorek

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: ee97698f854f42b4921ac7dca9cbeaaf2decae98
+refs/heads/try2: b64046a5b072a34a0940785a9301669a2ea00031
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/doc/guide-lifetimes.md

@@ -67,7 +67,7 @@ Now we can call `compute_distance()`:
 # let on_the_stack :     Point  =     Point{x: 3.0, y: 4.0};
 # let on_the_heap  : Box<Point> = box Point{x: 7.0, y: 9.0};
 # fn compute_distance(p1: &Point, p2: &Point) -> f64 { 0.0 }
-compute_distance(&on_the_stack, on_the_heap);
+compute_distance(&on_the_stack, &*on_the_heap);
 ~~~
 
 Here, the `&` operator takes the address of the variable
@@ -77,10 +77,9 @@ value. We also call this _borrowing_ the local variable
 `on_the_stack`, because we have created an alias: that is, another
 name for the same data.
 
-In the case of `on_the_heap`, however, no explicit action is necessary. 
-The compiler will automatically convert a box box point to a reference like &point. 
-This is another form of borrowing; in this case, the contents of the owned box 
-are being lent out.
+For the second argument, we need to extract the contents of `on_the_heap`
+by derefercing with the `*` symbol. Now that we have the data, we need
+to create a reference with the `&` symbol.
 
 Whenever a caller lends data to a callee, there are some limitations on what
 the caller can do with the original. For example, if the contents of a

branches/try2/src/doc/tutorial.md

@@ -1429,7 +1429,7 @@ contains a point, but allocated in a different location:
 ~~~
 # struct Point { x: f64, y: f64 }
 let on_the_stack :     Point  =     Point { x: 3.0, y: 4.0 };
-let on_the_heap  : Box<Point> = box Point { x: 7.0, y: 9.0 };
+let owned_box    : Box<Point> = box Point { x: 7.0, y: 9.0 };
 ~~~
 
 Suppose we want to write a procedure that computes the distance
@@ -1454,9 +1454,9 @@ Now we can call `compute_distance()` in various ways:
 ~~~
 # struct Point{ x: f64, y: f64 };
 # let on_the_stack :     Point  =     Point { x: 3.0, y: 4.0 };
-# let on_the_heap  : Box<Point> = box Point { x: 7.0, y: 9.0 };
+# let owned_box    : Box<Point> = box Point { x: 7.0, y: 9.0 };
 # fn compute_distance(p1: &Point, p2: &Point) -> f64 { 0.0 }
-compute_distance(&on_the_stack, on_the_heap);
+compute_distance(&on_the_stack, owned_box);
 ~~~
 
 Here the `&` operator is used to take the address of the variable

branches/try2/src/librustc/middle/typeck/check/_match.rs

@@ -87,7 +87,7 @@ pub fn check_match(fcx: &FnCtxt,
         result_ty =
             infer::common_supertype(
                 fcx.infcx(),
-                infer::MatchExpression(expr.span),
+                infer::MatchExpressionArm(expr.span, arm.body.span),
                 true, // result_ty is "expected" here
                 result_ty,
                 bty);
@@ -298,8 +298,9 @@ pub fn check_pat_variant(pcx: &pat_ctxt, pat: &ast::Pat, path: &ast::Path,
 /// `etc` is true if the pattern said '...' and false otherwise.
 pub fn check_struct_pat_fields(pcx: &pat_ctxt,
                                span: Span,
+                               path: &ast::Path,
                                fields: &[ast::FieldPat],
-                               class_fields: Vec<ty::field_ty>,
+                               class_fields: Vec<ty::field_ty> ,
                                class_id: ast::DefId,
                                substitutions: &ty::substs,
                                etc: bool) {
@@ -332,12 +333,13 @@ pub fn check_struct_pat_fields(pcx: &pat_ctxt,
                 found_fields.insert(index);
             }
             None => {
+                let name = pprust::path_to_str(path);
                 // Check the pattern anyway, so that attempts to look
                 // up its type won't fail
                 check_pat(pcx, field.pat, ty::mk_err());
                 tcx.sess.span_err(span,
                     format!("struct `{}` does not have a field named `{}`",
-                            ty::item_path_str(tcx, class_id),
+                            name,
                             token::get_ident(field.ident)).as_slice());
             }
         }
@@ -388,7 +390,7 @@ pub fn check_struct_pat(pcx: &pat_ctxt, pat_id: ast::NodeId, span: Span,
         }
     }
 
-    check_struct_pat_fields(pcx, span, fields, class_fields, struct_id,
+    check_struct_pat_fields(pcx, span, path, fields, class_fields, struct_id,
                             substitutions, etc);
 }
 
@@ -411,7 +413,7 @@ pub fn check_struct_like_enum_variant_pat(pcx: &pat_ctxt,
             // Get the struct fields from this struct-like enum variant.
             let class_fields = ty::lookup_struct_fields(tcx, variant_id);
 
-            check_struct_pat_fields(pcx, span, fields, class_fields,
+            check_struct_pat_fields(pcx, span, path, fields, class_fields,
                                     variant_id, substitutions, etc);
         }
         Some(&ast::DefStruct(..)) | Some(&ast::DefVariant(..)) => {

branches/try2/src/librustc/middle/typeck/infer/error_reporting.rs

@@ -346,7 +346,7 @@ impl<'a> ErrorReporting for InferCtxt<'a> {
             infer::ExprAssignable(_) => "mismatched types",
             infer::RelateTraitRefs(_) => "mismatched traits",
             infer::RelateSelfType(_) => "mismatched types",
-            infer::MatchExpression(_) => "match arms have incompatible types",
+            infer::MatchExpressionArm(_, _) => "match arms have incompatible types",
             infer::IfExpression(_) => "if and else have incompatible types",
         };
 
@@ -356,6 +356,12 @@ impl<'a> ErrorReporting for InferCtxt<'a> {
                  message_root_str,
                  expected_found_str,
                  ty::type_err_to_str(self.tcx, terr)).as_slice());
+
+        match trace.origin {
+            infer::MatchExpressionArm(_, arm_span) =>
+                self.tcx.sess.span_note(arm_span, "match arm with an incompatible type"),
+            _ => ()
+        }
     }
 
     fn report_and_explain_type_error(&self,
@@ -1281,7 +1287,7 @@ impl<'a> ErrorReportingHelpers for InferCtxt<'a> {
                     infer::RelateSelfType(_) => {
                         format!("type matches impl")
                     }
-                    infer::MatchExpression(_) => {
+                    infer::MatchExpressionArm(_, _) => {
                         format!("match arms have compatible types")
                     }
                     infer::IfExpression(_) => {

branches/try2/src/librustc/middle/typeck/infer/mod.rs

@@ -116,8 +116,8 @@ pub enum TypeOrigin {
     // Relating trait refs when resolving vtables
     RelateSelfType(Span),
 
-    // Computing common supertype in a match expression
-    MatchExpression(Span),
+    // Computing common supertype in the arms of a match expression
+    MatchExpressionArm(Span, Span),
 
     // Computing common supertype in an if expression
     IfExpression(Span),
@@ -831,7 +831,7 @@ impl TypeOrigin {
             Misc(span) => span,
             RelateTraitRefs(span) => span,
             RelateSelfType(span) => span,
-            MatchExpression(span) => span,
+            MatchExpressionArm(match_span, _) => match_span,
             IfExpression(span) => span,
         }
     }
@@ -853,8 +853,8 @@ impl Repr for TypeOrigin {
             RelateSelfType(a) => {
                 format!("RelateSelfType({})", a.repr(tcx))
             }
-            MatchExpression(a) => {
-                format!("MatchExpression({})", a.repr(tcx))
+            MatchExpressionArm(a, b) => {
+                format!("MatchExpressionArm({}, {})", a.repr(tcx), b.repr(tcx))
             }
             IfExpression(a) => {
                 format!("IfExpression({})", a.repr(tcx))

branches/try2/src/test/compile-fail/issue-14541.rs renamed to branches/try2/src/test/compile-fail/issue-11319.rs

@@ -8,13 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-struct vec2 { y: f32 }
-struct vec3 { y: f32, z: f32 }
-
-fn make(v: vec2) {
-    let vec3 { y: _, z: _ } = v;
-    //~^ ERROR mismatched types: expected `vec2` but found `vec3`
-    //~^^ ERROR struct `vec2` does not have a field named `z`
+fn main() {
+    match Some(10) {
+    //~^ ERROR match arms have incompatible types: expected `bool` but found `()`
+        Some(5) => false,
+        Some(2) => true,
+        None    => (), //~ NOTE match arm with an incompatible type
+        _       => true
+    }
 }
-
-fn main() { }