std::filesystem::path support

include/alpaca/alpaca.h

@@ -12,6 +12,7 @@
 #include <alpaca/detail/types/array.h>
 #include <alpaca/detail/types/deque.h>
 #include <alpaca/detail/types/duration.h>
+#include <alpaca/detail/types/filesystem_path.h>
 #include <alpaca/detail/types/list.h>
 #include <alpaca/detail/types/map.h>
 #include <alpaca/detail/types/optional.h>

include/alpaca/detail/field_type.h

@@ -34,7 +34,8 @@ enum class field_type : uint8_t {
   struct_,
   chrono_duration,
   list,
-  deque
+  deque,
+  filesystem_path
 };
 
 template <field_type value> constexpr uint8_t to_byte() {
@@ -43,4 +44,4 @@ template <field_type value> constexpr uint8_t to_byte() {
 
 } // namespace detail
 
-} // namespace alpaca
+} // namespace alpaca

include/alpaca/detail/to_bytes.h

@@ -85,4 +85,4 @@ to_bytes(T &bytes, std::size_t &byte_index, const U &value) {
 
 } // namespace detail
 
-} // namespace alpaca
+} // namespace alpaca

include/alpaca/detail/type_info.h

@@ -6,6 +6,10 @@
 #include <array>
 #endif
 
+#ifndef ALPACA_EXCLUDE_SUPPORT_STD_FILESYSTEM_PATH
+#include <filesystem>
+#endif
+
 #ifndef ALPACA_EXCLUDE_SUPPORT_STD_MAP
 #include <map>
 #endif
@@ -169,6 +173,15 @@ typename std::enable_if<is_array_type<T>::value, void>::type type_info(
     std::unordered_map<std::string_view, std::size_t> &struct_visitor_map);
 #endif
 
+#ifndef ALPACA_EXCLUDE_SUPPORT_STD_FILESYSTEM_PATH
+// filesystem::path
+template <typename T>
+typename std::enable_if<std::is_same<T, std::filesystem::path>::value, void>::type
+type_info(
+    std::vector<uint8_t> &typeids,
+    std::unordered_map<std::string_view, std::size_t> &struct_visitor_map);
+#endif
+
 #ifndef ALPACA_EXCLUDE_SUPPORT_STD_MAP
 // map
 template <typename T>
@@ -270,4 +283,4 @@ type_info(
 
 } // namespace detail
 
-} // namespace alpaca
+} // namespace alpaca

include/alpaca/detail/types/filesystem_path.h

@@ -0,0 +1,79 @@
+#pragma once
+#ifndef ALPACA_EXCLUDE_SUPPORT_STD_FILESYSTEM_PATH
+#include <alpaca/detail/from_bytes.h>
+#include <alpaca/detail/to_bytes.h>
+#include <alpaca/detail/type_info.h>
+#include <filesystem>
+#include <system_error>
+#include <vector>
+
+namespace alpaca {
+
+namespace detail {
+
+template <typename T>
+typename std::enable_if<std::is_same<T, std::filesystem::path>::value,
+                        void>::type
+type_info(std::vector<uint8_t> &typeids,
+          std::unordered_map<std::string_view, std::size_t> &) {
+  typeids.push_back(to_byte<field_type::filesystem_path>());
+}
+
+template <options O, typename T, typename Container>
+void to_bytes_router(const T &input, Container &bytes, std::size_t &byte_index);
+
+template <options O, typename Container>
+void to_bytes(Container &bytes, std::size_t &byte_index,
+              const std::filesystem::path &input) {
+  // save string length
+  to_bytes_router<O>(input.native().size(), bytes, byte_index);
+
+  for (const auto &c : input.native()) {
+    to_bytes<O>(bytes, byte_index, c);
+  }
+}
+
+template <options O, typename Container>
+bool from_bytes(std::filesystem::path &value, Container &bytes,
+           std::size_t &current_index, std::size_t &end_index,
+           std::error_code &error_code) {
+
+  if (current_index >= end_index) {
+    // end of input
+    // return true for forward compatibility
+    return true;
+  }
+
+  // current byte is the length of the string
+  std::size_t size = 0;
+  detail::from_bytes<O, std::size_t>(size, bytes, current_index, end_index,
+                                     error_code);
+
+  if (size > end_index - current_index) {
+    // size is greater than the number of bytes remaining
+    error_code = std::make_error_code(std::errc::value_too_large);
+
+    // stop here
+    return false;
+  }
+
+  // read `size` bytes and save to value
+  std::filesystem::path::string_type buff;
+  using CharType = std::filesystem::path::value_type;
+
+  buff.reserve(size * sizeof(CharType));
+
+  for (std::size_t i = 0; i < size; ++i) {
+    CharType character{};
+    from_bytes<O>(character, bytes, current_index, end_index, error_code);
+    buff += character;
+  }
+
+  value = std::move(buff);
+  return true;
+}
+
+} // namespace detail
+
+} // namespace alpaca
+#endif