Add type_conversion helper and failing unit test

include/chaiscript/dispatchkit/type_conversions.hpp

@@ -394,6 +394,19 @@ namespace chaiscript
       return std::make_shared<detail::Type_Conversion_Impl<decltype(func)>>(user_type<From>(), user_type<To>(), func);
     }
 
+  template<typename From, typename To>
+    Type_Conversion type_conversion()
+    {
+      static_assert(std::is_convertible<From, To>::value, "Types are not automatically convertible");
+      auto func = [](const Boxed_Value &t_bv) -> Boxed_Value {
+            // not even attempting to call boxed_cast so that we don't get caught in some call recursion
+            auto to = To{detail::Cast_Helper<const From &>::cast(t_bv, nullptr)};
+            return chaiscript::Boxed_Value(std::move(to));
+          };
+
+      return std::make_shared<detail::Type_Conversion_Impl<decltype(func)>>(user_type<From>(), user_type<To>(), func);
+    }
+
 }
 
 

src/test_module.cpp

@@ -28,7 +28,8 @@ class Type2
 {
   public:
     Type2(TestBaseType t_bt)
-      : m_bt(std::move(t_bt))
+      : m_bt(std::move(t_bt)),
+        m_str("Hello World")
     {
     }
 
@@ -37,8 +38,14 @@ class Type2
       return m_bt.val;
     }
 
+    const char *get_str() const
+    {
+      return m_str.c_str();
+    }
+
   private:
     TestBaseType m_bt;
+    std::string m_str;
 };
 
 enum TestEnum
@@ -158,6 +165,9 @@ CHAISCRIPT_MODULE_EXPORT  chaiscript::ModulePtr create_chaiscript_module_test_mo
   m->add(chaiscript::type_conversion<TestBaseType, Type2>([](const TestBaseType &t_bt) { return Type2(t_bt); }));
 
   m->add(chaiscript::fun(&Type2::get_val), "get_val");
+  m->add(chaiscript::fun(&Type2::get_str), "get_str");
+  m->add(chaiscript::type_conversion<const char *, std::string>());
+
   return m;
 }
 

unittests/user_defined_conversions_2.chai

@@ -7,3 +7,4 @@ auto t := TestBaseType();
 // "get_val()" which exists on the Type2 type
 assert_equal(t.get_val(), 10);
 
+assert_equal(t.get_str().size(), 11);