Add code to compara two enums values and add copy_from methode

Author: martinfantini

src/mfast/coder/encoder_v2/fast_encoder_core.h

@@ -2,6 +2,7 @@
 
 #include "../mfast_coder_export.h"
 #include "../../sequence_ref.h"
+#include "../../enum_ref.h"
 #include "../../nested_message_ref.h"
 #include "../../malloc_allocator.h"
 #include "../common/template_repo.h"
@@ -31,6 +32,11 @@ inline bool equivalent(const decimal_cref &v, const value_storage &prev) {
          v.exponent() == prev.of_decimal.exponent_;
 }
 
+inline bool equivalent(const enum_cref &v, const value_storage &prev) {
+  return v.absent() == prev.is_empty() &&
+         v.value() == prev.of_uint64.content_;
+}
+
 template <typename T>
 inline bool equivalent(const vector_cref<T> &v, const value_storage &prev) {
   return v.size() == prev.of_array.len_ - 1 &&

src/mfast/enum_ref.h

@@ -97,6 +97,11 @@ class enum_mref : public make_field_mref<enum_cref> {
     *this->storage() = this->instruction()->initial_value();
   }
   value_type value() const { return this->storage()->get<value_type>(); }
+
+protected:
+  friend class mfast::detail::codec_helper;
+
+  void copy_from(value_storage v) const { *this->storage() = v; }
 };
 
 template <> struct mref_of<enum_cref> { typedef enum_mref type; };