CMake: Proper way to require c++98 standard

cmake/compilerFlags.cmake

@@ -32,12 +32,6 @@ if ( MINGW OR UNIX OR MSYS ) # MINGW, Linux, APPLE, CYGWIN
 
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wcast-align -Wpointer-arith -Wformat-security -Wmissing-format-attribute -Woverloaded-virtual -W")
 
-        if ( CYGWIN OR (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 5.0))
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++98") # to support snprintf
-        else()
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++98")
-        endif()
-
         if ( EXIV2_TEAM_USE_SANITIZERS )
             # ASAN is available in gcc from 4.8 and UBSAN from 4.9
             # ASAN is available in clang from 3.1 and UBSAN from 3.3

cmake/mainSetup.cmake

@@ -15,6 +15,10 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
 set(CMAKE_CXX_VISIBILITY_PRESET hidden)
 set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
 
+set(CMAKE_CXX_STANDARD 98)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS ON)
+
 if (UNIX)
     if (APPLE)
         set(CMAKE_MACOSX_RPATH ON)