Add Clang support, be explicit about MSVC flags

Author: mrjoel

example/CMakeLists.txt

@@ -10,9 +10,9 @@ set(EXAMPLES
 add_definitions(-D_GLIBCXX_USE_CXX11_ABI)
 set_property(DIRECTORY PROPERTY COMPILE_OPTIONS ${EXTRA_CXX_FLAGS})
 
-if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra ")
-else()
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
     add_definitions(
         -D_SCL_SECURE_NO_WARNINGS
         -D_CRT_SECURE_NO_WARNINGS