DRTVWR-558: Extend LL::apply() to LLSD array arguments.

Make apply(function, std::array) and apply(function, std::vector) available
even when we borrow the C++17 implementation of apply(function, std::tuple).

Add apply(function, LLSD) with interpretations:

* isUndefined() is treated as an empty array, for calling a nullary function
* scalar LLSD is treated as a single-entry array, for calling a unary function
* isArray() converts function parameters using LLSDParam
* isMap() is an error.

Add unit tests for all flavors of LL::apply().

(cherry picked from commit 3006c24251c6259d00df9e0f4f66b8a617e6026d)

1 files changed, 171 insertions, 0 deletions

diff --git a/indra/llcommon/tests/apply_test.cpp b/indra/llcommon/tests/apply_test.cpp
new file mode 100644
index 0000000000..1f1085a702
--- /dev/null
+++ b/indra/llcommon/tests/apply_test.cpp
@@ -0,0 +1,171 @@
+/**
+ * @file   apply_test.cpp
+ * @author Nat Goodspeed
+ * @date   2022-12-19
+ * @brief  Test for apply.
+ * 
+ * $LicenseInfo:firstyear=2022&license=viewerlgpl$
+ * Copyright (c) 2022, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "apply.h"
+// STL headers
+// std headers
+// external library headers
+// other Linden headers
+#include "../test/lltut.h"
+#include "llsd.h"
+#include "llsdutil.h"
+
+/*****************************************************************************
+*   TUT
+*****************************************************************************/
+namespace tut
+{
+    namespace statics
+    {
+        /*------------------------------ data ------------------------------*/
+        // Although we're using types from the LLSD namespace, we're not
+        // constructing LLSD values, but rather instances of the C++ types
+        // supported by LLSD.
+        static LLSD::Boolean b{true};
+        static LLSD::Integer i{17};
+        static LLSD::Real    f{3.14};
+        static LLSD::String  s{ "hello" };
+        static LLSD::UUID    uu{ "baadf00d-dead-beef-baad-feedb0ef" };
+        static LLSD::Date    dt{ "2022-12-19" };
+        static LLSD::URI     uri{ "http://secondlife.com" };
+        static LLSD::Binary  bin{ 0x01, 0x02, 0x03, 0x04, 0x05 };
+
+        static std::vector<LLSD::String> quick
+        {
+            "The", "quick", "brown", "fox", "etc."
+        };
+
+        static std::array<int, 5> fibs
+        {
+            0, 1, 1, 2, 3
+        };
+
+        // ensure that apply() actually reaches the target method --
+        // lack of ensure_equals() failure could be due to no-op apply()
+        bool called{ false };
+
+        /*------------------------- test functions -------------------------*/
+        void various(LLSD::Boolean b, LLSD::Integer i, LLSD::Real f, const LLSD::String& s,
+                     const LLSD::UUID& uu, const LLSD::Date& dt,
+                     const LLSD::URI& uri, const LLSD::Binary& bin)
+        {
+            called = true;
+            ensure_equals(  "b mismatch", b,   statics::b);
+            ensure_equals(  "i mismatch", i,   statics::i);
+            ensure_equals(  "f mismatch", f,   statics::f);
+            ensure_equals(  "s mismatch", s,   statics::s);
+            ensure_equals( "uu mismatch", uu,  statics::uu);
+            ensure_equals( "dt mismatch", dt,  statics::dt);
+            ensure_equals("uri mismatch", uri, statics::uri);
+            ensure_equals("bin mismatch", bin, statics::bin);
+        }
+
+        void strings(std::string s0, std::string s1, std::string s2, std::string s3, std::string s4)
+        {
+            called = true;
+            ensure_equals("s0 mismatch", s0, statics::quick[0]);
+            ensure_equals("s1 mismatch", s1, statics::quick[1]);
+            ensure_equals("s2 mismatch", s2, statics::quick[2]);
+            ensure_equals("s3 mismatch", s3, statics::quick[3]);
+            ensure_equals("s4 mismatch", s4, statics::quick[4]);
+        }
+
+        void ints(int i0, int i1, int i2, int i3, int i4)
+        {
+            called = true;
+            ensure_equals("i0 mismatch", i0, statics::fibs[0]);
+            ensure_equals("i1 mismatch", i1, statics::fibs[1]);
+            ensure_equals("i2 mismatch", i2, statics::fibs[2]);
+            ensure_equals("i3 mismatch", i3, statics::fibs[3]);
+            ensure_equals("i4 mismatch", i4, statics::fibs[4]);
+        }
+
+        void intfunc(int i)
+        {
+            called = true;
+            ensure_equals("i mismatch", i, statics::i);
+        }
+
+        void voidfunc()
+        {
+            called = true;
+        }
+    } // namespace statics
+
+    struct apply_data
+    {
+        apply_data()
+        {
+            // reset called before each test
+            statics::called = false;
+        }
+    };
+    typedef test_group<apply_data> apply_group;
+    typedef apply_group::object object;
+    apply_group applygrp("apply");
+
+    template<> template<>
+    void object::test<1>()
+    {
+        set_test_name("apply(tuple)");
+        LL::apply(statics::various,
+                  std::make_tuple(statics::b, statics::i, statics::f, statics::s,
+                                  statics::uu, statics::dt, statics::uri, statics::bin));
+        ensure("apply(tuple) failed", statics::called);
+    }
+
+    template<> template<>
+    void object::test<2>()
+    {
+        set_test_name("apply(array)");
+        LL::apply(statics::ints, statics::fibs);
+        ensure("apply(array) failed", statics::called);
+    }
+
+    template<> template<>
+    void object::test<3>()
+    {
+        set_test_name("apply(vector)");
+        LL::apply(statics::strings, statics::quick);
+        ensure("apply(vector) failed", statics::called);
+    }
+
+    // The various apply(LLSD) tests exercise only the success cases because
+    // the failure cases trigger assert() fail, which is hard to catch.
+    template<> template<>
+    void object::test<4>()
+    {
+        set_test_name("apply(LLSD())");
+        LL::apply(statics::voidfunc, LLSD());
+        ensure("apply(LLSD()) failed", statics::called);
+    }
+
+    template<> template<>
+    void object::test<5>()
+    {
+        set_test_name("apply(LLSD scalar)");
+        LL::apply(statics::intfunc, LLSD(statics::i));
+        ensure("apply(LLSD scalar) failed", statics::called);
+    }
+
+    template<> template<>
+    void object::test<6>()
+    {
+        set_test_name("apply(LLSD array)");
+        LL::apply(statics::various,
+                  llsd::array(statics::b, statics::i, statics::f, statics::s,
+                              statics::uu, statics::dt, statics::uri, statics::bin));
+        ensure("apply(LLSD array) failed", statics::called);
+    }
+} // namespace tut