auto merge of #5125 : nikomatsakis/rust/issue-4846-lifetime-defaults, r=nikomatsakis

Work towards #4846.

- Institute new region defaults where all omitted regions get a fresh lifetime.
- Require explicit region names except in functions.
- Fix a bug in region parameterization inference.  I've been putting this off because it will not be important when we remove RP inference in favor of explicit declarations, but then it was blocking this patch.

r? @pcwalton

Author: bors

doc/rust.md

@@ -1144,22 +1144,23 @@ Constants are declared with the `const` keyword.
 A constant item must have an expression giving its definition.
 The definition expression of a constant is limited to expression forms that can be evaluated at compile time.
 
-Constants must be explicitly typed. The type may be ```bool```, ```char```, a number, or a type derived from
-those primitive types. The derived types are borrowed pointers, static arrays, tuples, and structs.
+Constants must be explicitly typed. The type may be ```bool```, ```char```, a number, or a type derived from those primitive types.
+The derived types are borrowed pointers, static arrays, tuples, and structs.
+Borrowed pointers must be have the `'static` lifetime.
 
 ~~~~
 const bit1: uint = 1 << 0;
 const bit2: uint = 1 << 1;
 
 const bits: [uint * 2] = [bit1, bit2];
-const string: &str = "bitstring";
+const string: &'static str = "bitstring";
 
 struct BitsNStrings {
     mybits: [uint *2],
-    mystring: &str
+    mystring: &'self str
 }
 
-const bits_n_strings: BitsNStrings = BitsNStrings {
+const bits_n_strings: BitsNStrings<'static> = BitsNStrings {
     mybits: bits,
     mystring: string
 };
@@ -1630,7 +1631,7 @@ The following are examples of structure expressions:
 ~~~~
 # struct Point { x: float, y: float }
 # struct TuplePoint(float, float);
-# mod game { pub struct User { name: &str, age: uint, score: uint } }
+# mod game { pub struct User<'self> { name: &'self str, age: uint, score: uint } }
 # struct Cookie; fn some_fn<T>(t: T) {}
 Point {x: 10f, y: 20f};
 TuplePoint(10f, 20f);
@@ -2556,8 +2557,8 @@ order specified by the tuple type.
 An example of a tuple type and its use:
 
 ~~~~
-type Pair = (int,&str);
-let p: Pair = (10,"hello");
+type Pair<'self> = (int,&'self str);
+let p: Pair<'static> = (10,"hello");
 let (a, b) = p;
 assert b != "world";
 ~~~~
@@ -2718,7 +2719,7 @@ fn add(x: int, y: int) -> int {
 
 let mut x = add(5,7);
 
-type Binop = fn(int,int) -> int;
+type Binop<'self> = &'self fn(int,int) -> int;
 let bo: Binop = add;
 x = bo(5,7);
 ~~~~~~~~

doc/tutorial.md

@@ -1951,7 +1951,7 @@ trait Printable {
 Traits may be implemented for specific types with [impls]. An impl
 that implements a trait includes the name of the trait at the start of
 the definition, as in the following impls of `Printable` for `int`
-and `&str`.
+and `~str`.
 
 [impls]: #functions-and-methods
 
@@ -1961,12 +1961,12 @@ impl Printable for int {
     fn print(&self) { io::println(fmt!("%d", *self)) }
 }
 
-impl Printable for &str {
+impl Printable for ~str {
     fn print(&self) { io::println(*self) }
 }
 
 # 1.print();
-# ("foo").print();
+# (~"foo").print();
 ~~~~
 
 Methods defined in an implementation of a trait may be called just like

src/libcore/at_vec.rs

@@ -168,7 +168,7 @@ pub mod traits {
     use kinds::Copy;
     use ops::Add;
 
-    impl<T:Copy> Add<&[const T],@[T]> for @[T] {
+    impl<T:Copy> Add<&self/[const T],@[T]> for @[T] {
         #[inline(always)]
         pure fn add(&self, rhs: & &self/[const T]) -> @[T] {
             append(*self, (*rhs))

src/libcore/cleanup.rs

@@ -22,8 +22,8 @@ use cast::transmute;
  * NB: These must match the representation in the C++ runtime.
  */
 
-type DropGlue = fn(**TypeDesc, *c_void);
-type FreeGlue = fn(**TypeDesc, *c_void);
+type DropGlue = &self/fn(**TypeDesc, *c_void);
+type FreeGlue = &self/fn(**TypeDesc, *c_void);
 
 type TaskID = uintptr_t;
 

src/libcore/condition.rs

@@ -22,10 +22,10 @@ pub struct Handler<T, U> {
 
 pub struct Condition<T, U> {
     name: &static/str,
-    key: task::local_data::LocalDataKey<Handler<T, U>>
+    key: task::local_data::LocalDataKey/&self<Handler<T, U>>
 }
 
-pub impl<T, U> Condition<T, U> {
+pub impl<T, U> Condition/&self<T, U> {
     fn trap(&self, h: &self/fn(T) -> U) -> Trap/&self<T, U> {
         unsafe {
             let p : *RustClosure = ::cast::transmute(&h);
@@ -65,11 +65,11 @@ pub impl<T, U> Condition<T, U> {
 }
 
 struct Trap<T, U> {
-    cond: &Condition<T, U>,
+    cond: &self/Condition/&self<T, U>,
     handler: @Handler<T, U>
 }
 
-pub impl<T, U> Trap<T, U> {
+pub impl<T, U> Trap/&self<T, U> {
     fn in<V>(&self, inner: &self/fn() -> V) -> V {
         unsafe {
             let _g = Guard { cond: self.cond };
@@ -81,10 +81,10 @@ pub impl<T, U> Trap<T, U> {
 }
 
 struct Guard<T, U> {
-    cond: &Condition<T, U>
+    cond: &self/Condition/&self<T, U>
 }
 
-impl<T, U> Drop for Guard<T, U> {
+impl<T, U> Drop for Guard/&self<T, U> {
     fn finalize(&self) {
         unsafe {
             debug!("Guard: popping handler from TLS");

src/libcore/container.rs

@@ -10,7 +10,6 @@
 
 //! Container traits
 
-use cmp::Equiv;
 use option::Option;
 
 pub trait Container {

src/libcore/gc.rs

@@ -115,7 +115,7 @@ unsafe fn is_safe_point(pc: *Word) -> Option<SafePoint> {
     return None;
 }
 
-type Visitor = fn(root: **Word, tydesc: *Word) -> bool;
+type Visitor = &self/fn(root: **Word, tydesc: *Word) -> bool;
 
 // Walks the list of roots for the given safe point, and calls visitor
 // on each root.

src/libcore/hash.rs

@@ -298,7 +298,7 @@ impl io::Writer for SipState {
     }
 }
 
-impl Streaming for &SipState {
+impl Streaming for SipState {
 
     #[inline(always)]
     fn input(&self, buf: &[const u8]) {

src/libcore/hashmap.rs

@@ -268,7 +268,9 @@ pub mod linear {
         }
     }
 
-    impl<K:Hash + IterBytes + Eq,V> BaseIter<(&K, &V)> for LinearMap<K, V> {
+    impl<K:Hash + IterBytes + Eq,V>
+        BaseIter<(&self/K, &self/V)> for LinearMap<K, V>
+    {
         /// Visit all key-value pairs
         pure fn each(&self, blk: fn(&(&self/K, &self/V)) -> bool) {
             for uint::range(0, self.buckets.len()) |i| {

src/libcore/io.rs

@@ -585,11 +585,11 @@ pub fn file_reader(path: &Path) -> Result<@Reader, ~str> {
 
 // Byte readers
 pub struct BytesReader {
-    bytes: &[u8],
+    bytes: &self/[u8],
     mut pos: uint
 }
 
-impl Reader for BytesReader {
+impl Reader for BytesReader/&self {
     fn read(&self, bytes: &mut [u8], len: uint) -> uint {
         let count = uint::min(len, self.bytes.len() - self.pos);