make vec fns/methods take imm slices.

this also repairs the unsoundness in typing of unpack_slice,
which was silently converting a const ptr to an imm one.

Author: nikomatsakis

doc/tutorial.md

@@ -908,14 +908,13 @@ for the parameter list, as in `{|| ...}`.
 Partial application is done using the `bind` keyword in Rust.
 
 ~~~~
-let daynum = bind vec::position_elem(["mo", "tu", "we", "th",
-                                      "fr", "sa", "su"], _);
+let findx = bind str::find_char(_, 'x');
 ~~~~
 
 Binding a function produces a boxed closure (`fn@` type) in which some
 of the arguments to the bound function have already been provided.
-`daynum` will be a function taking a single string argument, and
-returning the day of the week that string corresponds to (if any).
+`findx` will be a function taking a single string argument, and
+returning the position where the letter `x` occurs.
 
 ## Iteration
 

src/libcore/core.rc

@@ -45,7 +45,7 @@ export swappable;
 export dvec, dvec_iter;
 
 // NDM seems to be necessary for resolve to work
-export vec_iter, option_iter;
+export option_iter;
 
 // FIXME: This creates some APIs that I do not want to commit to. It is
 // currently exported for the uv code in std, but when that code moves into
@@ -146,11 +146,6 @@ mod f64;
 mod str;
 mod ptr;
 mod vec;
-#[path="iter-trait"]
-mod vec_iter {
-    #[path = "vec.rs"]
-    mod inst;
-}
 mod bool;
 mod tuple;
 

src/libcore/core.rs

@@ -7,7 +7,6 @@ import option = option::option;
 import path = path::path;
 import str::extensions;
 import vec::extensions;
-import vec_iter::extensions;
 import option::extensions;
 import option_iter::extensions;
 import ptr::extensions;

src/libcore/io.rs

@@ -331,7 +331,7 @@ impl <T: writer, C> of writer for {base: T, cleanup: C} {
 
 impl of writer for *libc::FILE {
     fn write(v: [const u8]/&) unsafe {
-        vec::unpack_slice(v) {|vbuf, len|
+        vec::unpack_const_slice(v) {|vbuf, len|
             let nout = libc::fwrite(vbuf as *c_void, len, 1u, self);
             if nout < 1 as size_t {
                 #error("error writing buffer");
@@ -359,9 +359,9 @@ fn FILE_writer(f: *libc::FILE, cleanup: bool) -> writer {
 impl of writer for fd_t {
     fn write(v: [const u8]/&) unsafe {
         let mut count = 0u;
-        vec::unpack_slice(v) {|vbuf, len|
+        vec::unpack_const_slice(v) {|vbuf, len|
             while count < len {
-                let vb = ptr::offset(vbuf, count) as *c_void;
+                let vb = ptr::const_offset(vbuf, count) as *c_void;
                 let nout = libc::write(self, vb, len);
                 if nout < 0 as ssize_t {
                     #error("error writing buffer");

src/libcore/iter-trait/vec.rs

@@ -3,6 +3,7 @@
 export addr_of;
 export mut_addr_of;
 export offset;
+export const_offset;
 export mut_offset;
 export null;
 export is_null;
@@ -45,6 +46,12 @@ fn offset<T>(ptr: *T, count: uint) -> *T unsafe {
     (ptr as uint + count * sys::size_of::<T>()) as *T
 }
 
+#[doc = "Calculate the offset from a const pointer"]
+#[inline(always)]
+fn const_offset<T>(ptr: *const T, count: uint) -> *const T unsafe {
+    (ptr as uint + count * sys::size_of::<T>()) as *T
+}
+
 #[doc = "Calculate the offset from a mut pointer"]
 #[inline(always)]
 fn mut_offset<T>(ptr: *mut T, count: uint) -> *mut T {