spin-off rustdocs tuple code to libstd

2 files changed, 30 insertions, 1 deletions

diff --git a/src/libstd/std.rc b/src/libstd/std.rc
index d96b6b7b666..34297b1aaef 100644
--- a/src/libstd/std.rc
+++ b/src/libstd/std.rc
@@ -12,7 +12,7 @@ export c_vec, four, tri, util;
 export bitv, deque, fun_treemap, list, map, smallintmap, sort, treemap, ufind;
 export rope;
 export ebml, dbg, getopts, json, rand, sha1, term, time;
-export extfmt, test, tempfile;
+export extfmt, test, tempfile, tuple;
 // FIXME: generic_os and os_fs shouldn't be exported
 export generic_os, os, os_fs;
 
@@ -61,6 +61,7 @@ mod md4;
 mod tempfile;
 mod term;
 mod time;
+mod tuple;
 
 #[cfg(unicode)]
 mod unicode;
diff --git a/src/libstd/tuple.rs b/src/libstd/tuple.rs
new file mode 100644
index 00000000000..9d24f428d42
--- /dev/null
+++ b/src/libstd/tuple.rs
@@ -0,0 +1,28 @@
+/*
+Module: tuple
+*/
+
+// FIXME #1546: Would rather write fst<T, U>(+pair: (T, U)) -> T
+fn first<T:copy, U:copy>(pair: (T, U)) -> T {
+    let (t, _) = pair;
+    ret t;
+}
+
+fn second<T:copy, U:copy>(pair: (T, U)) -> U {
+    let (_, u) = pair;
+    ret u;
+}
+
+fn swap<T:copy, U:copy>(pair: (T, U)) -> (U, T) {
+    let (t, u) = pair;
+    ret (u, t);
+}
+
+
+#[test]
+fn test_tuple() {
+    assert first((948, 4039.48)) == 948;
+    assert second((34.5, "foo")) == "foo";
+    assert swap(('a', 2)) == (2, 'a');
+}
+