fix: flags handling

include/string_utils/cast.h

@@ -96,9 +96,10 @@ template <typename Out> bool cast(Out & out, std::string_view str) noexcept {
     return true;
 #if __has_include(<magic_enum.hpp>)
   } else if constexpr (std::is_enum_v<Out>) {
-    std::optional<Out> result = magic_enum::enum_cast<Out>(str);
+    constexpr auto type = magic_enum::as_flags<magic_enum::detail::is_flags_v<Out>>;
+    std::optional<Out> result = magic_enum::enum_cast<Out, type>(str);
     out = result.value_or(out);
-    return result;
+    return result.has_value();
 #endif
   } else if constexpr (std::is_integral_v<Out>) {
     using V = std::conditional_t<std::is_unsigned_v<Out>, unsigned long, long>;