Add more general TYPE_SAFE_ARITHMETIC_POLICY

This replaces TYPE_SAFE_ARITHMETIC_UB.

Fixes #106, closes #107.

Author: foonathan

CMakeLists.txt

@@ -36,11 +36,22 @@ else()
     set(_type_safe_enable_wrapper 0)
 endif()
 
-option(TYPE_SAFE_ARITHMETIC_UB "whether or not the undefined_behavior_arithmetic policy is used" ON)
-if(${TYPE_SAFE_ARITHMETIC_UB})
-    set(_type_safe_arithmetic_ub 1)
+set(TYPE_SAFE_ARITHMETIC_POLICY "ub" CACHE STRING "which policy (ub/checked/default) is going to be used")
+option(TYPE_SAFE_ARITHMETIC_UB "deprecated" ON)
+
+if(NOT ${TYPE_SAFE_ARITHMETIC_UB})
+    set(_type_safe_arithmetic_policy 0)
+    message(DEPRECATION "option TYPE_SAFE_ARITHMETIC_UB is deprecated, use TYPE_SAFE_ARITHMETIC_POLICY instead")
+    message(STATUS "arithmetic_policy_default is default_arithmetic")
+elseif(${TYPE_SAFE_ARITHMETIC_POLICY} STREQUAL "ub")
+    set(_type_safe_arithmetic_policy 1)
+    message(STATUS "arithmetic_policy_default is undefined_behavior_arithmetic")
+elseif(${TYPE_SAFE_ARITHMETIC_POLICY} STREQUAL "checked")
+    set(_type_safe_arithmetic_policy 2)
+    message(STATUS "arithmetic_policy_default is checked_arithmetic")
 else()
-    set(_type_safe_arithmetic_ub 0)
+    set(_type_safe_arithmetic_policy 0)
+    message(STATUS "arithmetic_policy_default is default_arithmetic")
 endif()
 
 # interface target
@@ -88,7 +99,7 @@ target_compile_definitions(type_safe INTERFACE
                                      TYPE_SAFE_ENABLE_ASSERTIONS=${_type_safe_enable_assertions}
                                      TYPE_SAFE_ENABLE_PRECONDITION_CHECKS=${_type_safe_enable_precondition_checks}
                                      TYPE_SAFE_ENABLE_WRAPPER=${_type_safe_enable_wrapper}
-                                     TYPE_SAFE_ARITHMETIC_UB=${_type_safe_arithmetic_ub})
+                                     TYPE_SAFE_ARITHMETIC_POLICY=${_type_safe_arithmetic_policy})
 target_link_libraries(type_safe INTERFACE debug_assert)
 
 if(MSVC)

README.md

@@ -74,7 +74,7 @@ Behavior can be customized with the following macros:
 
 * `TYPE_SAFE_ENABLE_ASSERTIONS` (default is `1`): whether or not assertions are enabled in this library
 * `TYPE_SAFE_ENABLE_WRAPPER` (default is `1`): whether or not the typedefs in `type_safe/types.hpp` use the wrapper classes
-* `TYPE_SAFE_ARITHMETIC_UB` (default is `1`): whether under/overflow in the better integer types is UB.
+* `TYPE_SAFE_ARITHMETIC_POLICY` (`ub`/`checked`/`default`, default is `ub`): whether under/overflow in the better integer types is UB, an exception, or the default behavior
 
 If you're using CMake there is the target `type_safe` available after you've called `add_subdirectory(path/to/type_safe)`.
 Simply link this target to your target and it will setup everything automagically.

include/type_safe/arithmetic_policy.hpp

@@ -237,14 +237,15 @@ class checked_arithmetic
     }
 };
 
-#if TYPE_SAFE_ARITHMETIC_UB
+#if TYPE_SAFE_ARITHMETIC_POLICY == 1
 /// The default `ArithmeticPolicy`.
 ///
-/// It depends on the [TYPE_SAFE_ARITHMETIC_UB]() macro,
-/// and is either [ts::undefined_behavior_arithmetic]() or [ts::default_arithmetic]().
-/// \exclude target
-/// \module types
+/// It depends on the [TYPE_SAFE_ARITHMETIC_POLICY]() macro,
+/// and is either [ts::undefined_behavior_arithmetic](), [ts::checked_arithmetic](), or
+/// [ts::default_arithmetic](). \exclude target \module types
 using arithmetic_policy_default = undefined_behavior_arithmetic;
+#elif TYPE_SAFE_ARITHMETIC_POLICY == 2
+using arithmetic_policy_default = checked_arithmetic;
 #else
 using arithmetic_policy_default = default_arithmetic;
 #endif

include/type_safe/config.hpp

@@ -29,12 +29,12 @@
 #    define TYPE_SAFE_ENABLE_WRAPPER 1
 #endif
 
-#ifndef TYPE_SAFE_ARITHMETIC_UB
-/// Controls whether [ts::arithmetic_policy_default]() is [ts::undefined_behavior_arithmetic]() or
-/// [ts::default_arithmetic]().
+#ifndef TYPE_SAFE_ARITHMETIC_POLICY
+/// Controls whether [ts::arithmetic_policy_default]() is [ts::undefined_behavior_arithmetic](),
+/// [ts::checked_arithmetic](), or [ts::default_arithmetic]().
 ///
 /// It is [ts::undefined_behavior_arithmetic]() by default.
-#    define TYPE_SAFE_ARITHMETIC_UB 1
+#    define TYPE_SAFE_ARITHMETIC_POLICY 1
 #endif
 
 #ifndef TYPE_SAFE_DELETE_FUNCTIONS