feat: add magic_enum if has_include

include/string_utils/cast.h

@@ -17,6 +17,10 @@
 #include <variant>
 #include <vector>
 
+#if __has_include(<magic_enum.hpp>)
+#include <magic_enum.hpp>
+#endif
+
 #include "string_utils/any_of.h"
 #include "string_utils/forwards.h"
 #include "string_utils/traits.h"
@@ -90,6 +94,12 @@ template <typename Out> bool cast(Out & out, std::string_view str) noexcept {
   } else if constexpr (std::is_constructible_v<Out, std::string_view>) {
     out = Out(str);
     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);
+    out = result.value_or(out);
+    return result;
+#endif
   } else if constexpr (std::is_integral_v<Out>) {
     using V = std::conditional_t<std::is_unsigned_v<Out>, unsigned long, long>;
     auto [tmp, success] = cast<V>(str);