From 735435bf964dcafdfc09d01ea644bbfbe725abd8 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Thu, 21 Apr 2011 16:44:17 -0700
Subject: [PATCH] stdlib: Add a pointer equality function to the standard
 library and a test case

---
 src/lib/Box.rs               |  8 ++++++++
 src/lib/std.rc               |  1 +
 src/rt/rust_builtin.cpp      |  5 +++++
 src/rt/rustrt.def.in         |  1 +
 src/test/run-pass/lib-box.rs | 12 ++++++++++++
 5 files changed, 27 insertions(+)
 create mode 100644 src/lib/Box.rs
 create mode 100644 src/test/run-pass/lib-box.rs

diff --git a/src/lib/Box.rs b/src/lib/Box.rs
new file mode 100644
index 00000000000..2d94c680bf8
--- /dev/null
+++ b/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; }
+
diff --git a/src/lib/std.rc b/src/lib/std.rc
index 7e9e06c2ac9..1056f375138 100644
--- a/src/lib/std.rc
+++ b/src/lib/std.rc
@@ -69,6 +69,7 @@ mod sha1;
 mod ebml;
 mod UFind;
 mod ExtFmt;
+mod Box;
 
 // Local Variables:
 // mode: rust;
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index c1aa5b59413..30e2eb3ddeb 100644
--- a/src/rt/rust_builtin.cpp
+++ b/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++
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index 9ea6bee4262..d724dd714cf 100644
--- a/src/rt/rustrt.def.in
+++ b/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
diff --git a/src/test/run-pass/lib-box.rs b/src/test/run-pass/lib-box.rs
new file mode 100644
index 00000000000..10f5e727110
--- /dev/null
+++ b/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));
+}
+