fix windows build error

CMakeLists.txt

@@ -4,6 +4,10 @@ CMAKE_MINIMUM_REQUIRED(VERSION 3.4)
 SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/")
 INCLUDE_DIRECTORIES("${CMAKE_SOURCE_DIR}/include/")
 
+if (WIN32)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--allow-multiple-definition")
+endif()
+
 IF(NOT CMAKE_BUILD_TYPE)
     SET(CMAKE_BUILD_TYPE Release)
 ENDIF()