[CMake] mini_required 2.6->3.5 and fix CXX_VERSION variable passed fr…

…om cmd

CMakeLists.txt

@@ -1,20 +1,21 @@
+CMAKE_MINIMUM_REQUIRED (VERSION 3.5)
 PROJECT(CPPJIEBA)
 
-CMAKE_MINIMUM_REQUIRED (VERSION 2.6)
-
 INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR}/deps/limonp/include
   ${PROJECT_SOURCE_DIR}/include)
 
 if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
     set (CMAKE_INSTALL_PREFIX "/usr/local/cppjieba" CACHE PATH "default install path" FORCE )
 endif()
 
-ADD_DEFINITIONS(-O3 -Wall -g)
-IF(APPLE) # mac os
-    ADD_DEFINITIONS(-std=c++0x)
+if(NOT DEFINED CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 11)
 endif()
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+ADD_DEFINITIONS(-O3 -Wall -g)
 
-ADD_SUBDIRECTORY(deps)
 ADD_SUBDIRECTORY(test)
 
 ENABLE_TESTING()