Fix -Wnon-virtual-dtor warning (#79).

Author: SergiusTheBest

include/plog/Record.h

@@ -205,6 +205,10 @@ namespace plog
             return m_file;
         }
 
+        virtual ~Record() // virtual destructor to satisfy -Wnon-virtual-dtor warning
+        {
+        }
+
     private:
         util::Time              m_time;
         const Severity          m_severity;

samples/CMakeLists.txt

@@ -33,7 +33,7 @@ if(MSVC)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4 /WX")
     string(REPLACE "/RTC1" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
 elseif(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANGXX)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wconversion -pedantic -Werror")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wconversion -Wnon-virtual-dtor -pedantic -Werror")
     set(CMAKE_CXX_VISIBILITY_PRESET hidden)
     set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
     checkObjCXX()