docs(furvm): document detail folder

Refs: #12

furvm/include/furvm/detail/handle.hpp

@@ -6,15 +6,24 @@
 namespace furvm {
 namespace detail {
 
+/**
+ * @brief Default specialization for header_has_refcount type trait.
+ */
 template <typename Header, typename = void>
 struct header_has_refcount : std::false_type {};
 
+/**
+ * @brief Specialization for header_has_refcount type trait.
+ */
 template <typename Header>
 struct header_has_refcount<Header,
     std::void_t<decltype(std::declval<Header&>().acquire()),
         decltype(std::declval<Header&>().release()),
         decltype(std::declval<Header&>().reference_count())>> : std::true_type {};
 
+/**
+ * @brief An alias for header_has_refcount's value.
+ */
 template <typename Header>
 static constexpr auto header_has_refcount_v = header_has_refcount<Header>::value;
 

furvm/include/furvm/detail/serialization.hpp

@@ -8,15 +8,69 @@
 namespace furvm {
 namespace detail {
 
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::int8_t value);
 std::ostream& serialize(std::ostream& os, std::int16_t value);
+
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::int32_t value);
 std::ostream& serialize(std::ostream& os, std::int64_t value);
+
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::uint8_t value);
+
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::uint16_t value);
+
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::uint32_t value);
+
+/**
+ * @brief Serializes an integer.
+ *
+ * @param os Output stream.
+ * @param value Integer.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, std::uint64_t value);
 
+/**
+ * @brief Serializes a string.
+ *
+ * @param os Output stream.
+ * @param value String.
+ * @return The output stream.
+ */
 std::ostream& serialize(std::ostream& os, const std::string& value);
 
 } // namespace detail