SL-16024: Introduce tuple.h with tuple_cons(), tuple_cdr().

These functions allow prepending or removing an item at the left end of an
arbitrary tuple -- for instance, to add a sequence key to a caller's data,
then remove it again when delivering the original tuple.

1 files changed, 47 insertions, 0 deletions

diff --git a/indra/llcommon/tests/tuple_test.cpp b/indra/llcommon/tests/tuple_test.cpp
new file mode 100644
index 0000000000..af94e2086c
--- /dev/null
+++ b/indra/llcommon/tests/tuple_test.cpp
@@ -0,0 +1,47 @@
+/**
+ * @file   tuple_test.cpp
+ * @author Nat Goodspeed
+ * @date   2021-10-04
+ * @brief  Test for tuple.
+ * 
+ * $LicenseInfo:firstyear=2021&license=viewerlgpl$
+ * Copyright (c) 2021, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "tuple.h"
+// STL headers
+// std headers
+// external library headers
+// other Linden headers
+#include "../test/lltut.h"
+
+/*****************************************************************************
+*   TUT
+*****************************************************************************/
+namespace tut
+{
+    struct tuple_data
+    {
+    };
+    typedef test_group<tuple_data> tuple_group;
+    typedef tuple_group::object object;
+    tuple_group tuplegrp("tuple");
+
+    template<> template<>
+    void object::test<1>()
+    {
+        set_test_name("tuple");
+        std::tuple<std::string, int> tup{ "abc", 17 };
+        std::tuple<int, std::string, int> ptup{ tuple_cons(34, tup) };
+        std::tuple<std::string, int> tup2;
+        int i;
+        std::tie(i, tup2) = tuple_split(ptup);
+        ensure_equals("tuple_car() fail", i, 34);
+        ensure_equals("tuple_cdr() (0) fail", std::get<0>(tup2), "abc");
+        ensure_equals("tuple_cdr() (1) fail", std::get<1>(tup2), 17);
+    }
+} // namespace tut