diff --git a/test/buffer_test.cpp b/test/buffer_test.cpp
index 67d6167..0ddbf8f 100644
--- a/test/buffer_test.cpp
+++ b/test/buffer_test.cpp
@@ -30,89 +30,89 @@ namespace
   void check_size()
   {
 
-    BOOST_TEST_EQ(sizeof(big_float32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(big_float64_buf_t), 8);
-    BOOST_TEST_EQ(sizeof(little_float32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(little_float64_buf_t), 8);
-    BOOST_TEST_EQ(sizeof(native_float32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(native_float64_buf_t), 8);
+    BOOST_TEST_EQ(sizeof(big_float32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(big_float64_buf_t), 8u);
+    BOOST_TEST_EQ(sizeof(little_float32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(little_float64_buf_t), 8u);
+    BOOST_TEST_EQ(sizeof(native_float32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(native_float64_buf_t), 8u);
 
-    BOOST_TEST_EQ(sizeof(big_float32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(big_float64_buf_ut), 8);
-    BOOST_TEST_EQ(sizeof(little_float32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(little_float64_buf_ut), 8);
-    BOOST_TEST_EQ(sizeof(native_float32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(native_float64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(big_float32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(big_float64_buf_ut), 8u);
+    BOOST_TEST_EQ(sizeof(little_float32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(little_float64_buf_ut), 8u);
+    BOOST_TEST_EQ(sizeof(native_float32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(native_float64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(big_int8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(big_int16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(big_int24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(big_int32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(big_int40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(big_int48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(big_int56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(big_int64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(big_int8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(big_int16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(big_int24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(big_int32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(big_int40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(big_int48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(big_int56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(big_int64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(big_uint8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(big_uint16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(big_uint24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(big_uint32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(big_uint40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(big_uint48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(big_uint56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(big_uint64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(big_uint8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(big_uint16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(big_uint24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(big_uint32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(big_uint40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(big_uint48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(big_uint56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(big_uint64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(little_int8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(little_int16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(little_int24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(little_int32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(little_int40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(little_int48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(little_int56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(little_int64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(little_int8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(little_int16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(little_int24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(little_int32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(little_int40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(little_int48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(little_int56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(little_int64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(little_uint8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(little_uint16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(little_uint24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(little_uint32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(little_uint40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(little_uint48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(little_uint56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(little_uint64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(little_uint8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(little_uint16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(little_uint24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(little_uint32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(little_uint40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(little_uint48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(little_uint56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(little_uint64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(native_int8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(native_int16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(native_int24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(native_int32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(native_int40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(native_int48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(native_int56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(native_int64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(native_int8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(native_int16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(native_int24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(native_int32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(native_int40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(native_int48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(native_int56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(native_int64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(native_uint8_buf_ut), 1);
-    BOOST_TEST_EQ(sizeof(native_uint16_buf_ut), 2);
-    BOOST_TEST_EQ(sizeof(native_uint24_buf_ut), 3);
-    BOOST_TEST_EQ(sizeof(native_uint32_buf_ut), 4);
-    BOOST_TEST_EQ(sizeof(native_uint40_buf_ut), 5);
-    BOOST_TEST_EQ(sizeof(native_uint48_buf_ut), 6);
-    BOOST_TEST_EQ(sizeof(native_uint56_buf_ut), 7);
-    BOOST_TEST_EQ(sizeof(native_uint64_buf_ut), 8);
+    BOOST_TEST_EQ(sizeof(native_uint8_buf_ut), 1u);
+    BOOST_TEST_EQ(sizeof(native_uint16_buf_ut), 2u);
+    BOOST_TEST_EQ(sizeof(native_uint24_buf_ut), 3u);
+    BOOST_TEST_EQ(sizeof(native_uint32_buf_ut), 4u);
+    BOOST_TEST_EQ(sizeof(native_uint40_buf_ut), 5u);
+    BOOST_TEST_EQ(sizeof(native_uint48_buf_ut), 6u);
+    BOOST_TEST_EQ(sizeof(native_uint56_buf_ut), 7u);
+    BOOST_TEST_EQ(sizeof(native_uint64_buf_ut), 8u);
 
-    BOOST_TEST_EQ(sizeof(big_int16_buf_t), 2);
-    BOOST_TEST_EQ(sizeof(big_int32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(big_int64_buf_t), 8);
+    BOOST_TEST_EQ(sizeof(big_int16_buf_t), 2u);
+    BOOST_TEST_EQ(sizeof(big_int32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(big_int64_buf_t), 8u);
 
-    BOOST_TEST_EQ(sizeof(big_uint16_buf_t), 2);
-    BOOST_TEST_EQ(sizeof(big_uint32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(big_uint64_buf_t), 8);
+    BOOST_TEST_EQ(sizeof(big_uint16_buf_t), 2u);
+    BOOST_TEST_EQ(sizeof(big_uint32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(big_uint64_buf_t), 8u);
 
-    BOOST_TEST_EQ(sizeof(little_int16_buf_t), 2);
-    BOOST_TEST_EQ(sizeof(little_int32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(little_int64_buf_t), 8);
+    BOOST_TEST_EQ(sizeof(little_int16_buf_t), 2u);
+    BOOST_TEST_EQ(sizeof(little_int32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(little_int64_buf_t), 8u);
 
-    BOOST_TEST_EQ(sizeof(little_uint16_buf_t), 2);
-    BOOST_TEST_EQ(sizeof(little_uint32_buf_t), 4);
-    BOOST_TEST_EQ(sizeof(little_uint64_buf_t), 8);
+    BOOST_TEST_EQ(sizeof(little_uint16_buf_t), 2u);
+    BOOST_TEST_EQ(sizeof(little_uint32_buf_t), 4u);
+    BOOST_TEST_EQ(sizeof(little_uint64_buf_t), 8u);
   } // check_size
 
   //  test_inserter_and_extractor  -----------------------------------------------------//
diff --git a/test/endian_operations_test.cpp b/test/endian_operations_test.cpp
index de9e76e..caa7088 100644
--- a/test/endian_operations_test.cpp
+++ b/test/endian_operations_test.cpp
@@ -14,30 +14,18 @@
 
 //  See endian_test for tests of endianess correctness, size, and value.
 
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-//
-//
-//  TODO: transition to BOOST_TEST; more testing can only help
-//
-//
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-//----------------------------------------------------------------------------//
-
 #define BOOST_ENDIAN_LOG
 
 #include <boost/endian/detail/disable_warnings.hpp>
 
 #ifdef _MSC_VER
-# pragma warning( disable : 4242 )  // conversion ..., possible loss of data
-# pragma warning( disable : 4244 )  // conversion ..., possible loss of data
-# pragma warning( disable : 4018 )  // signed/unsigned mismatch
-# pragma warning( disable : 4365 )  // signed/unsigned mismatch
-# pragma warning( disable : 4389 )  // signed/unsigned mismatch
+#  pragma warning( disable : 4242 )  // conversion ..., possible loss of data
+#  pragma warning( disable : 4244 )  // conversion ..., possible loss of data
+#  pragma warning( disable : 4018 )  // signed/unsigned mismatch
+#  pragma warning( disable : 4365 )  // signed/unsigned mismatch
+#  pragma warning( disable : 4389 )  // signed/unsigned mismatch
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic ignored "-Wconversion"
 #endif
 
 #define BOOST_ENDIAN_LOG
@@ -90,7 +78,7 @@ struct construct
   static void test()
   {
     T2 o2(1);
-    T1 o1(o2);   // TODO: does this make sense for char types?
+    T1 o1(static_cast<T1>(o2));
     ++o1;  // quiet gcc unused variable warning
   }
 };