Auto merge of #28685 - steveklabnik:rollup, r=steveklabnik

- Successful merges: #28666, #28674, #28677, #28678, #28679, #28680
- Failed merges: #28621

src/doc/README.md

@@ -2,9 +2,10 @@
 
 ## Building
 
-To generate all the docs, just run `make docs` from the root of the repository.
-This will convert the distributed Markdown docs to HTML and generate HTML doc
-for the 'std' and 'extra' libraries.
+To generate all the docs, follow the "Building Documentation" instructions in
+the README in the root of the repository. This will convert the distributed
+Markdown docs to HTML and generate HTML doc for the books, 'std' and 'extra'
+libraries.
 
 To generate HTML documentation from one source file/crate, do something like:
 

src/doc/reference.md

@@ -881,7 +881,7 @@ mod foo {
     }
 
     use foo::example::iter; // good: foo is at crate root
-//  use example::iter;      // bad:  core is not at the crate root
+//  use example::iter;      // bad:  example is not at the crate root
     use self::baz::foobaz;  // good: self refers to module 'foo'
     use foo::bar::foobar;   // good: foo is at crate root
 

src/doc/trpl/iterators.md

@@ -150,15 +150,16 @@ let greater_than_forty_two = (0..100)
                              .find(|x| *x > 42);
 
 match greater_than_forty_two {
-    Some(_) => println!("We got some numbers!"),
-    None => println!("No numbers found :("),
+    Some(_) => println!("Found a match!"),
+    None => println!("No match found :("),
 }
 ```
 
 `find` takes a closure, and works on a reference to each element of an
 iterator. This closure returns `true` if the element is the element we're
-looking for, and `false` otherwise. Because we might not find a matching
-element, `find` returns an `Option` rather than the element itself.
+looking for, and `false` otherwise. `find` returns the first element satisfying
+the specified predicate. Because we might not find a matching element, `find`
+returns an `Option` rather than the element itself.
 
 Another important consumer is `fold`. Here's what it looks like:
 

src/doc/trpl/structs.md

@@ -184,6 +184,8 @@ You can define a `struct` with no members at all:
 
 ```rust
 struct Electron;
+
+let x = Electron;
 ```
 
 Such a `struct` is called ‘unit-like’ because it resembles the empty

src/libcore/ops.rs

@@ -1628,7 +1628,7 @@ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 /// impl<T> Deref for DerefExample<T> {
 ///     type Target = T;
 ///
-///     fn deref<'a>(&'a self) -> &'a T {
+///     fn deref(&self) -> &T {
 ///         &self.value
 ///     }
 /// }

src/librustc/middle/check_const.rs

@@ -709,20 +709,26 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
             if !is_const {
                 v.add_qualif(ConstQualif::NOT_CONST);
                 if v.mode != Mode::Var {
+                    fn span_limited_call_error(tcx: &ty::ctxt, span: Span, s: &str) {
+                        span_err!(tcx.sess, span, E0015, "{}", s);
+                    }
+
                     // FIXME(#24111) Remove this check when const fn stabilizes
                     if let UnstableFeatures::Disallow = v.tcx.sess.opts.unstable_features {
-                        span_err!(v.tcx.sess, e.span, E0015,
-                                  "function calls in {}s are limited to \
-                                   struct and enum constructors", v.msg());
+                        span_limited_call_error(&v.tcx, e.span,
+                                                &format!("function calls in {}s are limited to \
+                                                          struct and enum constructors",
+                                                         v.msg()));
                         v.tcx.sess.span_note(e.span,
                                              "a limited form of compile-time function \
                                               evaluation is available on a nightly \
                                               compiler via `const fn`");
                     } else {
-                        span_err!(v.tcx.sess, e.span, E0015,
-                                  "function calls in {}s are limited to \
-                                   constant functions, \
-                                   struct and enum constructors", v.msg());
+                        span_limited_call_error(&v.tcx, e.span,
+                                                &format!("function calls in {}s are limited \
+                                                          to constant functions, \
+                                                          struct and enum constructors",
+                                                         v.msg()));
                     }
                 }
             }