Add auto_save property

src/xtd.core/include/xtd/configuration/file_settings.h

@@ -60,11 +60,21 @@ namespace xtd {
       file_settings(file_settings&&) noexcept = default;
       file_settings(const file_settings&) noexcept = default;
       file_settings& operator =(const file_settings&) noexcept = default;
+      ~file_settings();
       /// @endcond
 
       /// @name Public Properties
 
       /// @{
+      /// @brief Gets whether save should be called on the xtd::configuration::file_settings destructor.
+      /// @return true if xtd::configuration::file_settings::save is called on the xtd::configuration::file_settings destructor; otherwise, false.
+      /// @remarks The default is false.
+      bool auto_save() const noexcept;
+      /// @brief Sets whether save should be called on the xtd::configuration::file_settings destructor.
+      /// @param value true if xtd::configuration::file_settings::save is called on the xtd::configuration::file_settings destructor; otherwise, false.
+      /// @remarks The default is false.
+      void auto_save(bool value) noexcept;
+
       /// @brief Gets the file path of the current instance.
       /// @return The file path of the current instance.
       /// @remarks If no file the property can be return xtd::ustring::empty_string.
@@ -94,6 +104,11 @@ namespace xtd {
       /// @brief Gets all sections.
       /// @return The sections vector.
       string_vector sections() const noexcept;
+
+      /// @brief Gets the stream of the current instance.
+      /// @return The stream of the current instance.
+      /// @warning Don't manipulate the stream yourself, otherwise the expected result may be undefined.
+      std::optional<std::reference_wrapper<std::iostream>> stream() const noexcept;
       /// @}
 
       /// @name Public Methods
@@ -261,8 +276,9 @@ namespace xtd {
       xtd::ustring read_string(const xtd::ustring& section, const xtd::ustring& key, const xtd::ustring& default_value) noexcept;
       void write_string(const xtd::ustring& section, const xtd::ustring& key, const xtd::ustring& value) noexcept;
 
-      std::map<xtd::ustring, string_map> section_key_values_;
+      bool auto_save_ = false;
       xtd::ustring file_path_;
+      std::map<xtd::ustring, string_map> section_key_values_;
       std::iostream* stream_ = nullptr;
     };
   }

src/xtd.core/src/xtd/configuration/file_settings.cpp

@@ -15,6 +15,17 @@ file_settings::file_settings(iostream& stream) : stream_ {&stream} {
   load(*stream_);
 }
 
+file_settings::~file_settings() {
+  if (auto_save_) save();
+}
+
+bool file_settings::auto_save() const noexcept {
+  return auto_save_;
+}
+void file_settings::auto_save(bool value) noexcept {
+  auto_save_ = value;
+}
+
 const xtd::ustring& file_settings::file_path() const noexcept {
   return file_path_;
 }
@@ -47,6 +58,10 @@ file_settings::string_vector file_settings::sections() const noexcept {
   return sections;
 }
 
+optional<reference_wrapper<iostream>> file_settings::stream() const noexcept {
+  return stream_ ? optional<reference_wrapper<iostream>> {} : optional<reference_wrapper<iostream>> {*stream_};
+}
+
 bool file_settings::equals(const file_settings& obj) const noexcept {
   return section_key_values_ == obj.section_key_values_;
 }
@@ -102,12 +117,12 @@ void file_settings::remove_all_keys(const ustring& section) noexcept {
 void file_settings::reset() {
   section_key_values_.clear();
   if (!ustring::is_empty(file_path_) && file::exists(file_path_)) file::remove(file_path_);
-  if (stream_ != nullptr) stream_writer(*stream_).write("");
+  if (stream_) stream_writer(*stream_).write("");
 }
 
 void file_settings::save() {
   if (!ustring::is_empty(file_path_)) save_as(file_path_);
-  if (stream_ != nullptr) save_as(*stream_);
+  if (stream_) save_as(*stream_);
 }
 
 void file_settings::save_as(const xtd::ustring& file_path) {