refactor: the default dowcasting mode changed from AUTO to ON

conanfile.py

@@ -52,7 +52,7 @@ class UnitsConan(ConanFile):
         "downcast": ["off", "on", "auto"]
     }
     default_options = {
-        "downcast": "auto"
+        "downcast": "on"
     }
     exports = ["LICENSE.md"]
     exports_sources = ["docs/*", "src/*", "test/*", "cmake/*", "example/*","CMakeLists.txt"]

src/CMakeLists.txt

@@ -27,7 +27,7 @@ project(mp-units
     LANGUAGES CXX
 )
 
-set(DOWNCAST_MODE AUTO CACHE STRING "Select downcasting mode")
+set(DOWNCAST_MODE ON CACHE STRING "Select downcasting mode")
 set_property(CACHE DOWNCAST_MODE PROPERTY STRINGS AUTO ON OFF)
 
 # set path to custom cmake modules

src/include/units/bits/external/downcasting.h

@@ -30,7 +30,7 @@
 #error "Invalid DOWNCAST_MODE value"
 #endif
 #else
-#define DOWNCAST_MODE 2
+#define DOWNCAST_MODE 1
 #endif
 
 namespace units {