netplay: introduce custom error category for getaddrinfo() error codes

Signed-off-by: Pavel Solodovnikov <[email protected]>

lib/netplay/error_categories.cpp

@@ -98,13 +98,29 @@ std::error_condition GenericSystemErrorCategory::default_error_condition(int ev)
 	return std::system_category().default_error_condition(ev);
 }
 
+std::string GetaddrinfoErrorCategory::message(int ev) const
+{
+	return gai_strerror(ev);
+}
+
 const std::error_category& generic_system_error_category()
 {
 	static GenericSystemErrorCategory instance;
 	return instance;
 }
 
+const std::error_category& getaddrinfo_error_category()
+{
+	static GetaddrinfoErrorCategory instance;
+	return instance;
+}
+
 std::error_code make_network_error_code(int ev)
 {
 	return { ev, generic_system_error_category() };
 }
+
+std::error_code make_getaddrinfo_error_code(int ev)
+{
+	return { ev, getaddrinfo_error_category() };
+}

lib/netplay/error_categories.h

@@ -47,6 +47,26 @@ class GenericSystemErrorCategory : public std::error_category
 	std::error_condition default_error_condition(int ev) const noexcept override;
 };
 
+/// <summary>
+/// Custom error category which maps error codes from `getaddrinfo()` function to
+/// the appropriate error messages.
+/// </summary>
+class GetaddrinfoErrorCategory : public std::error_category
+{
+public:
+
+	constexpr GetaddrinfoErrorCategory() = default;
+
+	const char* name() const noexcept override
+	{
+		return "getaddrinfo";
+	}
+
+	std::string message(int ev) const override;
+};
+
 const std::error_category& generic_system_error_category();
+const std::error_category& getaddrinfo_error_category();
 
 std::error_code make_network_error_code(int ev);
+std::error_code make_getaddrinfo_error_code(int ev);