COMP: allow building against 4.13 out of source

Author: dzenanz

CMakeLists.txt

@@ -6,28 +6,26 @@ cmake_minimum_required(VERSION 3.10.2)
 if(NOT ITK_SOURCE_DIR)
   find_package(ITK REQUIRED)
   list(APPEND CMAKE_MODULE_PATH ${ITK_CMAKE_DIR})
-  if(ITK_VERSION_MAJOR GREATER 4 )
-    if(NOT CMAKE_CXX_STANDARD)
-      set(CMAKE_CXX_STANDARD 11) # Supported values are ``11``, ``14``, and ``17``.
-    endif()
-    if(NOT CMAKE_CXX_STANDARD_REQUIRED)
-      set(CMAKE_CXX_STANDARD_REQUIRED ON)
-    endif()
-    if(NOT CMAKE_CXX_EXTENSIONS)
-      set(CMAKE_CXX_EXTENSIONS OFF)
-    endif()
-
-    foreach(p
-        ## Only policies introduced after the cmake_minimum_required
-        ## version need to explicitly be set to NEW.
-        CMP0070 #3.10.0 Define ``file(GENERATE)`` behavior for relative paths.
-        CMP0071 #3.10.0 Let ``AUTOMOC`` and ``AUTOUIC`` process ``GENERATED`` files.
-        )
-      if(POLICY ${p})
-        cmake_policy(SET ${p} NEW)
-      endif()
-    endforeach()
+  if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 11) # Supported values are ``11``, ``14``, and ``17``.
   endif()
+  if(NOT CMAKE_CXX_STANDARD_REQUIRED)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+  endif()
+  if(NOT CMAKE_CXX_EXTENSIONS)
+    set(CMAKE_CXX_EXTENSIONS OFF)
+  endif()
+
+  foreach(p
+      ## Only policies introduced after the cmake_minimum_required
+      ## version need to explicitly be set to NEW.
+      CMP0070 #3.10.0 Define ``file(GENERATE)`` behavior for relative paths.
+      CMP0071 #3.10.0 Let ``AUTOMOC`` and ``AUTOUIC`` process ``GENERATED`` files.
+      )
+    if(POLICY ${p})
+      cmake_policy(SET ${p} NEW)
+    endif()
+  endforeach()
 
 
   # Set a default build type if none was specified