Add test_pragma_pack

test/CMakeLists.txt

@@ -19,6 +19,7 @@ boost_test(TYPE run SOURCES test_uuid_2.cpp)
 
 boost_test(TYPE run SOURCES test_alignment.cpp)
 boost_test(TYPE run SOURCES test_attribute_packed.cpp)
+boost_test(TYPE run SOURCES test_pragma_pack.cpp)
 boost_test(TYPE run SOURCES test_data.cpp)
 
 boost_test(TYPE run SOURCES test_comparison.cpp COMPILE_DEFINITIONS BOOST_UUID_REPORT_IMPLEMENTATION=1)

test/Jamfile.v2

@@ -62,6 +62,7 @@ run test_uuid_2.cpp ;
 
 run test_alignment.cpp ;
 run test_attribute_packed.cpp ;
+run test_pragma_pack.cpp ;
 run test_data.cpp ;
 
 # test comparison

test/test_pragma_pack.cpp

@@ -0,0 +1,49 @@
+// Copyright 2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/uuid/uuid.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <cstddef>
+
+#if !defined(__GNUC__) && !defined(_MSC_VER)
+
+BOOST_PRAGMA_MESSAGE( "Test skipped, __GNUC__ and _MSC_VER are not defined" )
+int main() {}
+
+#else
+
+using namespace boost::uuids;
+
+#pragma pack( push, 1 )
+
+struct X1
+{
+    unsigned char a;
+    uuid b;
+    unsigned char c;
+};
+
+struct X2
+{
+    uuid a;
+    unsigned char b;
+    unsigned c;
+    unsigned char d;
+};
+
+#pragma pack( pop )
+
+int main()
+{
+    BOOST_TEST_EQ( offsetof(X1, b), 1 );
+    BOOST_TEST_EQ( sizeof(X1), 18 );
+
+    BOOST_TEST_EQ( offsetof(X2, c), 17 );
+    BOOST_TEST_EQ( sizeof(X2), 22 );
+
+    return boost::report_errors();
+}
+
+#endif