From 26c822559b89468817f140034ed7890ce6b17638 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Mon, 4 Nov 2024 13:33:00 +0200
Subject: [PATCH] Add test/append_zero_sized.cpp

---
 test/Jamfile               |  2 ++
 test/append_pointer.cpp    |  2 +-
 test/append_zero_sized.cpp | 63 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 test/append_zero_sized.cpp

diff --git a/test/Jamfile b/test/Jamfile
index a713a19..fecfe2c 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -73,6 +73,8 @@ run hash_append_5.cpp ;
 run hash_append_range.cpp ;
 run hash_append_range_2.cpp ;
 
+run append_zero_sized.cpp ;
+
 # hash_append, constexpr
 
 compile append_byte_sized_cx.cpp ;
diff --git a/test/append_pointer.cpp b/test/append_pointer.cpp
index 53b6213..c4fa2de 100644
--- a/test/append_pointer.cpp
+++ b/test/append_pointer.cpp
@@ -1,4 +1,4 @@
-// Copyright 2024 Peter Dimov.
+// Copyright 2024 Peter Dimov
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
diff --git a/test/append_zero_sized.cpp b/test/append_zero_sized.cpp
new file mode 100644
index 0000000..d5006b3
--- /dev/null
+++ b/test/append_zero_sized.cpp
@@ -0,0 +1,63 @@
+// Copyright 2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/hash2/hash_append.hpp>
+#include <boost/hash2/fnv1a.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/array.hpp>
+#include <array>
+
+template<class Hash, class Flavor, class T, class R> void test( T const* first, T const* last, R r )
+{
+    Hash h;
+    Flavor f;
+
+    boost::hash2::hash_append_range( h, f, first, last );
+
+    BOOST_TEST_EQ( h.result(), r );
+}
+
+struct X
+{
+};
+
+BOOST_DESCRIBE_STRUCT(X, (), ())
+
+// A hash_append call must always result in a call to Hash::update
+
+int main()
+{
+    using namespace boost::hash2;
+
+    {
+        boost::array<int, 0> v[ 3 ];
+    
+        test<fnv1a_32, default_flavor>( v + 0, v + 1, 84696351 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 2, 292984781 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 3, 1253111735 );
+    }
+
+    {
+        std::array<int, 0> v[ 3 ];
+    
+        test<fnv1a_32, default_flavor>( v + 0, v + 1, 84696351 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 2, 292984781 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 3, 1253111735 );
+    }
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+    {
+        X v[ 3 ];
+    
+        test<fnv1a_32, default_flavor>( v + 0, v + 1, 84696351 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 2, 292984781 );
+        test<fnv1a_32, default_flavor>( v + 0, v + 3, 1253111735 );
+    }
+
+#endif
+
+    return boost::report_errors();
+}