stdlib: Add a pointer equality function to the standard library and a test case

src/lib/Box.rs

@@ -0,0 +1,8 @@
+export rustrt;
+
+native "rust" mod rustrt {
+    fn rust_ptr_eq[T](@T a, @T b) -> int;
+}
+
+fn ptr_eq[T](@T a, @T b) -> bool { ret rustrt.rust_ptr_eq[T](a, b) != 0; }
+

src/lib/std.rc

@@ -69,6 +69,7 @@ mod sha1;
 mod ebml;
 mod UFind;
 mod ExtFmt;
+mod Box;
 
 // Local Variables:
 // mode: rust;

src/rt/rust_builtin.cpp

@@ -468,6 +468,11 @@ rust_file_is_dir(rust_task *task, rust_str *path) {
 extern "C" CDECL FILE* rust_get_stdin() {return stdin;}
 extern "C" CDECL FILE* rust_get_stdout() {return stdout;}
 
+extern "C" CDECL int
+rust_ptr_eq(rust_task *task, type_desc *t, rust_box *a, rust_box *b) {
+    return a == b;
+}
+
 //
 // Local Variables:
 // mode: C++

src/rt/rustrt.def.in

@@ -19,6 +19,7 @@ rust_get_stdin
 rust_get_stdout
 rust_list_files
 rust_process_wait
+rust_ptr_eq
 rust_run_program
 rust_start
 size_of

src/test/run-pass/lib-box.rs

@@ -0,0 +1,12 @@
+use std;
+import std.Box;
+
+fn main() {
+    auto x = @3;
+    auto y = @3;
+    check (Box.ptr_eq[int](x, x));
+    check (Box.ptr_eq[int](y, y));
+    check (!Box.ptr_eq[int](x, y));
+    check (!Box.ptr_eq[int](y, x));
+}
+