change C++11 compare.

Author: freeeyes

CMakeLists.txt

@@ -8,9 +8,9 @@ project(PSS_alpha)
 if(UNIX)
 	#linux
 	include(CheckCXXCompilerFlag)
-	CHECK_CXX_COMPILER_FLAG("-std=c++17" COMPILER_SUPPORTS_CXX17)
-	if(COMPILER_SUPPORTS_CXX17)
-		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17")
+	CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
+	if(COMPILER_SUPPORTS_CXX11)
+		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 	endif()
 
 	#message("[pss build]build jemalloc begin")