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

Diff for: 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);
 ~~~~~~~~

Diff for: 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

Diff for: 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))

Diff for: 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;
 

Diff for: 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");

Diff for: src/libcore/container.rs

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

Diff for: 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.

Diff for: 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]) {

Diff for: 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| {

Diff for: 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);
 

Diff for: src/libcore/iter.rs

@@ -20,7 +20,7 @@ use option::{None, Option, Some};
 use vec;
 
 /// A function used to initialize the elements of a sequence
-pub type InitOp<T> = &fn(uint) -> T;
+pub type InitOp<T> = &self/fn(uint) -> T;
 
 pub trait BaseIter<A> {
     pure fn each(&self, blk: fn(v: &A) -> bool);

Diff for: src/libcore/os.rs

@@ -1028,11 +1028,11 @@ pub mod consts {
     pub use os::consts::windows::*;
 
     pub mod unix {
-        pub const FAMILY: &str = "unix";
+        pub const FAMILY: &static/str = "unix";
     }
 
     pub mod windows {
-        pub const FAMILY: &str = "windows";
+        pub const FAMILY: &static/str = "windows";
     }
 
     #[cfg(target_os = "macos")]
@@ -1051,38 +1051,38 @@ pub mod consts {
     pub use os::consts::win32::*;
 
     pub mod macos {
-        pub const SYSNAME: &str = "macos";
-        pub const DLL_PREFIX: &str = "lib";
-        pub const DLL_SUFFIX: &str = ".dylib";
-        pub const EXE_SUFFIX: &str = "";
+        pub const SYSNAME: &static/str = "macos";
+        pub const DLL_PREFIX: &static/str = "lib";
+        pub const DLL_SUFFIX: &static/str = ".dylib";
+        pub const EXE_SUFFIX: &static/str = "";
     }
 
     pub mod freebsd {
-        pub const SYSNAME: &str = "freebsd";
-        pub const DLL_PREFIX: &str = "lib";
-        pub const DLL_SUFFIX: &str = ".so";
-        pub const EXE_SUFFIX: &str = "";
+        pub const SYSNAME: &static/str = "freebsd";
+        pub const DLL_PREFIX: &static/str = "lib";
+        pub const DLL_SUFFIX: &static/str = ".so";
+        pub const EXE_SUFFIX: &static/str = "";
     }
 
     pub mod linux {
-        pub const SYSNAME: &str = "linux";
-        pub const DLL_PREFIX: &str = "lib";
-        pub const DLL_SUFFIX: &str = ".so";
-        pub const EXE_SUFFIX: &str = "";
+        pub const SYSNAME: &static/str = "linux";
+        pub const DLL_PREFIX: &static/str = "lib";
+        pub const DLL_SUFFIX: &static/str = ".so";
+        pub const EXE_SUFFIX: &static/str = "";
     }
 
     pub mod android {
-        pub const SYSNAME: &str = "android";
-        pub const DLL_PREFIX: &str = "lib";
-        pub const DLL_SUFFIX: &str = ".so";
-        pub const EXE_SUFFIX: &str = "";
+        pub const SYSNAME: &static/str = "android";
+        pub const DLL_PREFIX: &static/str = "lib";
+        pub const DLL_SUFFIX: &static/str = ".so";
+        pub const EXE_SUFFIX: &static/str = "";
     }
 
     pub mod win32 {
-        pub const SYSNAME: &str = "win32";
-        pub const DLL_PREFIX: &str = "";
-        pub const DLL_SUFFIX: &str = ".dll";
-        pub const EXE_SUFFIX: &str = ".exe";
+        pub const SYSNAME: &static/str = "win32";
+        pub const DLL_PREFIX: &static/str = "";
+        pub const DLL_SUFFIX: &static/str = ".dll";
+        pub const EXE_SUFFIX: &static/str = ".exe";
     }
 
 
@@ -1099,16 +1099,16 @@ pub mod consts {
     use os::consts::mips::*;
 
     pub mod x86 {
-        pub const ARCH: &str = "x86";
+        pub const ARCH: &'static str = "x86";
     }
     pub mod x86_64 {
-        pub const ARCH: &str = "x86_64";
+        pub const ARCH: &'static str = "x86_64";
     }
     pub mod arm {
-        pub const ARCH: &str = "arm";
+        pub const ARCH: &'static str = "arm";
     }
     pub mod mips {
-        pub const ARCH: &str = "mips";
+        pub const ARCH: &'static str = "mips";
     }
 }
 

Diff for: src/libcore/pipes.rs

@@ -440,7 +440,7 @@ pub fn try_recv<T:Owned,Tbuffer:Owned>(p: RecvPacketBuffered<T, Tbuffer>)
     let p = unsafe { &*p_ };
 
     struct DropState {
-        p: &PacketHeader,
+        p: &self/PacketHeader,
 
         drop {
             if task::failing() {

Diff for: src/libcore/ptr.rs

@@ -264,7 +264,7 @@ impl<T> Ord for *const T {
 
 // Equality for region pointers
 #[cfg(notest)]
-impl<T:Eq> Eq for &const T {
+impl<T:Eq> Eq for &self/const T {
     #[inline(always)]
     pure fn eq(&self, other: & &self/const T) -> bool {
         return *(*self) == *(*other);
@@ -277,7 +277,7 @@ impl<T:Eq> Eq for &const T {
 
 // Comparison for region pointers
 #[cfg(notest)]
-impl<T:Ord> Ord for &const T {
+impl<T:Ord> Ord for &self/const T {
     #[inline(always)]
     pure fn lt(&self, other: & &self/const T) -> bool {
         *(*self) < *(*other)

Diff for: src/libcore/str.rs

@@ -787,7 +787,7 @@ pure fn cmp(a: &str, b: &str) -> Ordering {
 }
 
 #[cfg(notest)]
-impl TotalOrd for &str {
+impl TotalOrd for &'self str {
     pure fn cmp(&self, other: & &self/str) -> Ordering { cmp(*self, *other) }
 }
 
@@ -833,7 +833,7 @@ pure fn gt(a: &str, b: &str) -> bool {
 }
 
 #[cfg(notest)]
-impl Eq for &str {
+impl Eq for &self/str {
     #[inline(always)]
     pure fn eq(&self, other: & &self/str) -> bool {
         eq_slice((*self), (*other))
@@ -875,7 +875,7 @@ impl Ord for ~str {
 }
 
 #[cfg(notest)]
-impl Ord for &str {
+impl Ord for &self/str {
     #[inline(always)]
     pure fn lt(&self, other: & &self/str) -> bool { lt((*self), (*other)) }
     #[inline(always)]
@@ -899,7 +899,7 @@ impl Ord for @str {
 }
 
 #[cfg(notest)]
-impl Equiv<~str> for &str {
+impl Equiv<~str> for &'self str {
     #[inline(always)]
     pure fn equiv(&self, other: &~str) -> bool { eq_slice(*self, *other) }
 }
@@ -2226,7 +2226,7 @@ pub mod traits {
     use ops::Add;
     use str::append;
 
-    impl Add<&str,~str> for ~str {
+    impl Add<&self/str,~str> for ~str {
         #[inline(always)]
         pure fn add(&self, rhs: & &self/str) -> ~str {
             append(copy *self, (*rhs))
@@ -2270,7 +2270,7 @@ pub trait StrSlice {
 }
 
 /// Extension methods for strings
-impl StrSlice for &str {
+impl StrSlice for &self/str {
     /**
      * Return true if a predicate matches all characters or if the string
      * contains no characters

Diff for: src/libcore/sys.rs

@@ -19,7 +19,7 @@ use libc::{c_void, c_char, size_t};
 use repr;
 use str;
 
-pub type FreeGlue = fn(*TypeDesc, *c_void);
+pub type FreeGlue = &self/fn(*TypeDesc, *c_void);
 
 // Corresponds to runtime type_desc type
 pub enum TypeDesc = {

Diff for: src/libcore/task/local_data.rs

@@ -44,7 +44,7 @@ use task::rt;
  *
  * These two cases aside, the interface is safe.
  */
-pub type LocalDataKey<T> = &fn(v: @T);
+pub type LocalDataKey<T> = &self/fn(v: @T);
 
 /**
  * Remove a task-local data value from the table, returning the