diff --git a/src/rust.rs b/src/rust.rs
index e345e68..c13d003 100644
--- a/src/rust.rs
+++ b/src/rust.rs
@@ -1,1501 +1,1504 @@
 use configuration::{
     Config, Function, ItemProperty, Object, ObjectType, Property, SimpleType, Type,
 };
 use std::io::{Result, Write};
 use util::{snake_case, write_if_different};
 
 fn rust_type(p: &Property) -> String {
     if p.optional {
         return format!("Option<{}>", p.property_type.rust_type());
     }
     p.property_type.rust_type().to_string()
 }
 
 fn rust_type_(p: &ItemProperty) -> String {
     if p.optional {
         return format!("Option<{}>", p.item_property_type.rust_type());
     }
     p.item_property_type.rust_type().to_string()
 }
 
 fn rust_return_type(p: &Property) -> String {
     let mut type_: String = p.property_type.rust_type().to_string();
     if type_ == "String" {
         type_ = "str".to_string();
     }
     if type_ == "Vec<u8>" {
         type_ = "[u8]".to_string();
     }
     if p.property_type.is_complex() {
         type_ = "&".to_string() + &type_;
     }
     if p.optional {
         return "Option<".to_string() + &type_ + ">";
     }
     type_
 }
 
 fn rust_return_type_(p: &ItemProperty) -> String {
     let mut type_: String = p.item_property_type.rust_type().to_string();
     if type_ == "String" && !p.rust_by_value {
         type_ = "str".to_string();
     }
     if type_ == "Vec<u8>" && !p.rust_by_value {
         type_ = "[u8]".to_string();
     }
     if p.item_property_type.is_complex() && !p.rust_by_value {
         type_ = "&".to_string() + &type_;
     }
     if p.optional {
         return "Option<".to_string() + &type_ + ">";
     }
     type_
 }
 
 fn rust_c_type(p: &ItemProperty) -> String {
     if p.optional {
         return format!("COption<{}>", p.item_property_type.rust_type());
     }
     p.item_property_type.rust_type().to_string()
 }
 
 fn rust_type_init(p: &Property) -> &str {
     if p.optional {
         return "None";
     }
     p.property_type.rust_type_init()
 }
 
 fn r_constructor_args_decl(r: &mut Vec<u8>, name: &str, o: &Object, conf: &Config) -> Result<()> {
     write!(r, "    {}: *mut {}QObject", snake_case(name), o.name)?;
     for (p_name, p) in &o.properties {
         if let Type::Object(object) = &p.property_type {
             writeln!(r, ",")?;
             r_constructor_args_decl(r, p_name, object, conf)?;
         } else {
             write!(
                 r,
                 ",\n    {}_{}_changed: fn(*const {}QObject)",
                 snake_case(name),
                 snake_case(p_name),
                 o.name
             )?;
         }
     }
     if o.object_type == ObjectType::List {
         write!(
             r,
             ",\n    {}_new_data_ready: fn(*const {}QObject)",
             snake_case(name),
             o.name
         )?;
     } else if o.object_type == ObjectType::Tree {
         write!(
             r,
             ",\n    {}_new_data_ready: fn(*const {}QObject, index: COption<usize>)",
             snake_case(name),
             o.name
         )?;
     }
     if o.object_type != ObjectType::Object {
         let index_decl = if o.object_type == ObjectType::Tree {
             " index: COption<usize>,"
         } else {
             ""
         };
         let dest_decl = if o.object_type == ObjectType::Tree {
             " index: COption<usize>,"
         } else {
             ""
         };
         write!(
             r,
             ",
     {2}_layout_about_to_be_changed: fn(*const {0}QObject),
     {2}_layout_changed: fn(*const {0}QObject),
     {2}_data_changed: fn(*const {0}QObject, usize, usize),
     {2}_begin_reset_model: fn(*const {0}QObject),
     {2}_end_reset_model: fn(*const {0}QObject),
     {2}_begin_insert_rows: fn(*const {0}QObject,{1} usize, usize),
     {2}_end_insert_rows: fn(*const {0}QObject),
     {2}_begin_move_rows: fn(*const {0}QObject,{1} usize, usize,{3} usize),
     {2}_end_move_rows: fn(*const {0}QObject),
     {2}_begin_remove_rows: fn(*const {0}QObject,{1} usize, usize),
     {2}_end_remove_rows: fn(*const {0}QObject)",
             o.name,
             index_decl,
             snake_case(name),
             dest_decl
         )?;
     }
     Ok(())
 }
 
 fn r_constructor_args(r: &mut Vec<u8>, name: &str, o: &Object, conf: &Config) -> Result<()> {
     for (name, p) in &o.properties {
         if let Type::Object(object) = &p.property_type {
             r_constructor_args(r, name, object, conf)?;
         }
     }
     writeln!(
         r,
         "    let {}_emit = {}Emitter {{
         qobject: Arc::new(Mutex::new({0})),",
         snake_case(name),
         o.name
     )?;
     for (p_name, p) in &o.properties {
         if p.is_object() {
             continue;
         }
         writeln!(
             r,
             "        {}_changed: {}_{0}_changed,",
             snake_case(p_name),
             snake_case(name)
         )?;
     }
     if o.object_type != ObjectType::Object {
         writeln!(
             r,
             "        new_data_ready: {}_new_data_ready,",
             snake_case(name)
         )?;
     }
     let mut model = String::new();
     if o.object_type != ObjectType::Object {
         let type_ = if o.object_type == ObjectType::List {
             "List"
         } else {
             "Tree"
         };
         model.push_str(", model");
         writeln!(
             r,
             "    }};
     let model = {}{} {{
         qobject: {},
         layout_about_to_be_changed: {2}_layout_about_to_be_changed,
         layout_changed: {2}_layout_changed,
         data_changed: {2}_data_changed,
         begin_reset_model: {2}_begin_reset_model,
         end_reset_model: {2}_end_reset_model,
         begin_insert_rows: {2}_begin_insert_rows,
         end_insert_rows: {2}_end_insert_rows,
         begin_move_rows: {2}_begin_move_rows,
         end_move_rows: {2}_end_move_rows,
         begin_remove_rows: {2}_begin_remove_rows,
         end_remove_rows: {2}_end_remove_rows,",
             o.name,
             type_,
             snake_case(name)
         )?;
     }
     write!(
         r,
         "    }};\n    let d_{} = {}::new({0}_emit{}",
         snake_case(name),
         o.name,
         model
     )?;
     for (name, p) in &o.properties {
         if p.is_object() {
             write!(r, ",\n        d_{}", snake_case(name))?;
         }
     }
     writeln!(r, ");")
 }
 
 fn write_function(
     r: &mut Vec<u8>,
     (name, f): (&String, &Function),
     lcname: &str,
     o: &Object,
 ) -> Result<()> {
     let lc = snake_case(name);
     write!(
         r,
         "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_{}(ptr: *{} {}",
         lcname,
         lc,
         if f.mutable { "mut" } else { "const" },
         o.name
     )?;
     // write all the input arguments, for QString and QByteArray, write
     // pointers to their content and the length which is int in Qt
     for a in &f.arguments {
         write!(r, ", ")?;
         if a.argument_type.name() == "QString" {
             write!(r, "{}_str: *const c_ushort, {0}_len: c_int", a.name)?;
         } else if a.argument_type.name() == "QByteArray" {
             write!(r, "{}_str: *const c_char, {0}_len: c_int", a.name)?;
         } else {
             write!(r, "{}: {}", a.name, a.argument_type.rust_type())?;
         }
     }
     // If the return type is QString or QByteArray, append a pointer to the
     // variable that will be set to the argument list. Also add a setter
     // function.
     if f.return_type.is_complex() {
         writeln!(
             r,
             ", d: *mut {}, set: fn(*mut {0}, str: *const c_char, len: c_int)) {{",
             f.return_type.name()
         )?;
     } else {
         writeln!(r, ") -> {} {{", f.return_type.rust_type())?;
     }
     for a in &f.arguments {
         if a.argument_type.name() == "QString" {
             writeln!(
                 r,
                 "    let mut {} = String::new();
     set_string_from_utf16(&mut {0}, {0}_str, {0}_len);",
                 a.name
             )?;
         } else if a.argument_type.name() == "QByteArray" {
             writeln!(
                 r,
                 "    let {} = {{ slice::from_raw_parts({0}_str as *const u8, to_usize({0}_len)) }};",
                 a.name
             )?;
         }
     }
     if f.mutable {
         writeln!(r, "    let o = &mut *ptr;")?;
     } else {
         writeln!(r, "    let o = &*ptr;")?;
     }
     write!(r, "    let r = o.{}(", lc)?;
     for (i, a) in f.arguments.iter().enumerate() {
         if i > 0 {
             write!(r, ", ")?;
         }
         write!(r, "{}", a.name)?;
     }
     writeln!(r, ");")?;
     if f.return_type.is_complex() {
         writeln!(
             r,
             "    let s: *const c_char = r.as_ptr() as (*const c_char);
     set(d, s, r.len() as i32);"
         )?;
     } else {
         writeln!(r, "    r")?;
     }
     writeln!(r, "}}")
 }
 
 fn write_rust_interface_object(r: &mut Vec<u8>, o: &Object, conf: &Config) -> Result<()> {
     let lcname = snake_case(&o.name);
     writeln!(
         r,
         "
 pub struct {}QObject {{}}
 
 #[derive(Clone)]
 pub struct {0}Emitter {{
     qobject: Arc<Mutex<*const {0}QObject>>,",
         o.name
     )?;
     for (name, p) in &o.properties {
         if p.is_object() {
             continue;
         }
         writeln!(
             r,
             "    {}_changed: fn(*const {}QObject),",
             snake_case(name),
             o.name
         )?;
     }
     if o.object_type == ObjectType::List {
         writeln!(r, "    new_data_ready: fn(*const {}QObject),", o.name)?;
     } else if o.object_type == ObjectType::Tree {
         writeln!(
             r,
             "    new_data_ready: fn(*const {}QObject, index: COption<usize>),",
             o.name
         )?;
     }
     writeln!(
         r,
         "}}
 
 unsafe impl Send for {}Emitter {{}}
 
 impl {0}Emitter {{
     fn clear(&self) {{
         *self.qobject.lock().unwrap() = null();
     }}",
         o.name
     )?;
 
     for (name, p) in &o.properties {
         if p.is_object() {
             continue;
         }
         writeln!(
             r,
             "    pub fn {}_changed(&self) {{
         let ptr = *self.qobject.lock().unwrap();
         if !ptr.is_null() {{
             (self.{0}_changed)(ptr);
         }}
     }}",
             snake_case(name)
         )?;
     }
 
     if o.object_type == ObjectType::List {
         writeln!(
             r,
             "    pub fn new_data_ready(&self) {{
         let ptr = *self.qobject.lock().unwrap();
         if !ptr.is_null() {{
             (self.new_data_ready)(ptr);
         }}
     }}"
         )?;
     } else if o.object_type == ObjectType::Tree {
         writeln!(
             r,
             "    pub fn new_data_ready(&self, item: Option<usize>) {{
         let ptr = *self.qobject.lock().unwrap();
         if !ptr.is_null() {{
             (self.new_data_ready)(ptr, item.into());
         }}
     }}"
         )?;
     }
 
     let mut model_struct = String::new();
     if o.object_type != ObjectType::Object {
         let type_ = if o.object_type == ObjectType::List {
             "List"
         } else {
             "Tree"
         };
         model_struct = format!(", model: {}{}", o.name, type_);
         let mut index = "";
         let mut index_decl = "";
         let mut index_c_decl = "";
         let mut dest = "";
         let mut dest_decl = "";
         let mut dest_c_decl = "";
         if o.object_type == ObjectType::Tree {
             index_decl = " index: Option<usize>,";
             index_c_decl = " index: COption<usize>,";
             index = " index.into(),";
             dest_decl = " dest: Option<usize>,";
             dest_c_decl = " dest: COption<usize>,";
             dest = " dest.into(),";
         }
         writeln!(
             r,
             "}}
 
 #[derive(Clone)]
 pub struct {0}{1} {{
     qobject: *const {0}QObject,
     layout_about_to_be_changed: fn(*const {0}QObject),
     layout_changed: fn(*const {0}QObject),
     data_changed: fn(*const {0}QObject, usize, usize),
     begin_reset_model: fn(*const {0}QObject),
     end_reset_model: fn(*const {0}QObject),
     begin_insert_rows: fn(*const {0}QObject,{4} usize, usize),
     end_insert_rows: fn(*const {0}QObject),
     begin_move_rows: fn(*const {0}QObject,{4} usize, usize,{7} usize),
     end_move_rows: fn(*const {0}QObject),
     begin_remove_rows: fn(*const {0}QObject,{4} usize, usize),
     end_remove_rows: fn(*const {0}QObject),
 }}
 
 impl {0}{1} {{
     pub fn layout_about_to_be_changed(&self) {{
         (self.layout_about_to_be_changed)(self.qobject);
     }}
     pub fn layout_changed(&self) {{
         (self.layout_changed)(self.qobject);
     }}
     pub fn data_changed(&self, first: usize, last: usize) {{
         (self.data_changed)(self.qobject, first, last);
     }}
     pub fn begin_reset_model(&self) {{
         (self.begin_reset_model)(self.qobject);
     }}
     pub fn end_reset_model(&self) {{
         (self.end_reset_model)(self.qobject);
     }}
     pub fn begin_insert_rows(&self,{2} first: usize, last: usize) {{
         (self.begin_insert_rows)(self.qobject,{3} first, last);
     }}
     pub fn end_insert_rows(&self) {{
         (self.end_insert_rows)(self.qobject);
     }}
     pub fn begin_move_rows(&self,{2} first: usize, last: usize,{5} destination: usize) {{
         (self.begin_move_rows)(self.qobject,{3} first, last,{6} destination);
     }}
     pub fn end_move_rows(&self) {{
         (self.end_move_rows)(self.qobject);
     }}
     pub fn begin_remove_rows(&self,{2} first: usize, last: usize) {{
         (self.begin_remove_rows)(self.qobject,{3} first, last);
     }}
     pub fn end_remove_rows(&self) {{
         (self.end_remove_rows)(self.qobject);
     }}",
             o.name, type_, index_decl, index, index_c_decl, dest_decl, dest, dest_c_decl
         )?;
     }
 
     write!(
         r,
         "}}
 
 pub trait {}Trait {{
     fn new(emit: {0}Emitter{}",
         o.name, model_struct
     )?;
     for (name, p) in &o.properties {
         if p.is_object() {
             write!(r, ",\n        {}: {}", snake_case(name), p.type_name())?;
         }
     }
     writeln!(
         r,
         ") -> Self;
     fn emit(&self) -> &{}Emitter;",
         o.name
     )?;
     for (name, p) in &o.properties {
         let lc = snake_case(name).to_lowercase();
         if p.is_object() {
             writeln!(r, "    fn {}(&self) -> &{};", lc, rust_type(p))?;
             writeln!(r, "    fn {}_mut(&mut self) -> &mut {};", lc, rust_type(p))?;
         } else {
             if p.rust_by_function {
                 write!(
                     r,
                     "    fn {}<F>(&self, getter: F) where F: FnOnce({});",
                     lc,
                     rust_return_type(p)
                 )?;
             } else {
                 writeln!(r, "    fn {}(&self) -> {};", lc, rust_return_type(p))?;
             }
             if p.write {
                 if p.type_name() == "QByteArray" {
                     if p.optional {
                         writeln!(r, "    fn set_{}(&mut self, value: Option<&[u8]>);", lc)?;
                     } else {
                         writeln!(r, "    fn set_{}(&mut self, value: &[u8]);", lc)?;
                     }
                 } else {
                     writeln!(r, "    fn set_{}(&mut self, value: {});", lc, rust_type(p))?;
                 }
             }
         }
     }
     for (name, f) in &o.functions {
         let lc = snake_case(name);
         let mut arg_list = String::new();
         if !f.arguments.is_empty() {
             for a in &f.arguments {
                 let t = if a.argument_type.name() == "QByteArray" {
                     "&[u8]"
                 } else {
                     a.argument_type.rust_type()
                 };
                 arg_list.push_str(&format!(", {}: {}", a.name, t));
             }
         }
         writeln!(
             r,
             "    fn {}(&{}self{}) -> {};",
             lc,
             if f.mutable { "mut " } else { "" },
             arg_list,
             f.return_type.rust_type()
         )?;
     }
     if o.object_type == ObjectType::List {
         writeln!(
             r,
             "    fn row_count(&self) -> usize;
     fn insert_rows(&mut self, _row: usize, _count: usize) -> bool {{ false }}
     fn remove_rows(&mut self, _row: usize, _count: usize) -> bool {{ false }}
     fn can_fetch_more(&self) -> bool {{
         false
     }}
     fn fetch_more(&mut self) {{}}
     fn sort(&mut self, u8, SortOrder) {{}}"
         )?;
     } else if o.object_type == ObjectType::Tree {
         writeln!(
             r,
             "    fn row_count(&self, Option<usize>) -> usize;
     fn can_fetch_more(&self, Option<usize>) -> bool {{
         false
     }}
     fn fetch_more(&mut self, Option<usize>) {{}}
     fn sort(&mut self, u8, SortOrder) {{}}
     fn check_row(&self, index: usize, row: usize) -> Option<usize>;
     fn index(&self, item: Option<usize>, row: usize) -> usize;
     fn parent(&self, index: usize) -> Option<usize>;
     fn row(&self, index: usize) -> usize;"
         )?;
     }
     if o.object_type != ObjectType::Object {
         for (name, ip) in &o.item_properties {
             let name = snake_case(name);
             writeln!(
                 r,
                 "    fn {}(&self, index: usize) -> {};",
                 name,
                 rust_return_type_(ip)
             )?;
             if ip.write {
                 if ip.item_property_type.name() == "QByteArray" {
                     if ip.optional {
                         writeln!(
                             r,
                             "    fn set_{}(&mut self, index: usize, Option<&[u8]>) -> bool;",
                             name
                         )?;
                     } else {
                         writeln!(
                             r,
                             "    fn set_{}(&mut self, index: usize, &[u8]) -> bool;",
                             name
                         )?;
                     }
                 } else {
                     writeln!(
                         r,
                         "    fn set_{}(&mut self, index: usize, {}) -> bool;",
                         name,
                         rust_type_(ip)
                     )?;
                 }
             }
         }
     }
     writeln!(
         r,
         "}}
 
 #[no_mangle]
 pub extern \"C\" fn {}_new(",
         lcname
     )?;
     r_constructor_args_decl(r, &lcname, o, conf)?;
     writeln!(r, ",\n) -> *mut {} {{", o.name)?;
     r_constructor_args(r, &lcname, o, conf)?;
     writeln!(
         r,
         "    Box::into_raw(Box::new(d_{}))
 }}
 
 #[no_mangle]
 pub unsafe extern \"C\" fn {0}_free(ptr: *mut {}) {{
     Box::from_raw(ptr).emit().clear();
 }}",
         lcname, o.name
     )?;
 
     for (name, p) in &o.properties {
         let base = format!("{}_{}", lcname, snake_case(name));
         if p.is_object() {
             writeln!(
                 r,
                 "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(ptr: *mut {}) -> *mut {} {{
     (&mut *ptr).{}_mut()
 }}",
                 base,
                 o.name,
                 rust_type(p),
                 snake_case(name)
             )?;
         } else if p.is_complex() && !p.optional {
             if p.rust_by_function {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(
     ptr: *const {},
     p: *mut {},
     set: fn(*mut {2}, *const c_char, c_int),
 ) {{
     let o = &*ptr;
     o.{}(|v| {{
         let s: *const c_char = v.as_ptr() as (*const c_char);
         set(p, s, to_c_int(v.len()));
     }});
 }}",
                     base,
                     o.name,
                     p.type_name(),
                     snake_case(name)
                 )?;
             } else {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(
     ptr: *const {},
     p: *mut {},
     set: fn(*mut {2}, *const c_char, c_int),
 ) {{
     let o = &*ptr;
     let v = o.{}();
     let s: *const c_char = v.as_ptr() as (*const c_char);
     set(p, s, to_c_int(v.len()));
 }}",
                     base,
                     o.name,
                     p.type_name(),
                     snake_case(name)
                 )?;
             }
             if p.write && p.type_name() == "QString" {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: *const c_ushort, len: c_int) {{
     let o = &mut *ptr;
     let mut s = String::new();
     set_string_from_utf16(&mut s, v, len);
     o.set_{}(s);
 }}",
                     base,
                     o.name,
                     snake_case(name)
                 )?;
             } else if p.write {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: *const c_char, len: c_int) {{
     let o = &mut *ptr;
     let v = slice::from_raw_parts(v as *const u8, to_usize(len));
     o.set_{}(v);
 }}",
                     base,
                     o.name,
                     snake_case(name)
                 )?;
             }
         } else if p.is_complex() {
             writeln!(
                 r,
                 "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(
     ptr: *const {},
     p: *mut {},
     set: fn(*mut {2}, *const c_char, c_int),
 ) {{
     let o = &*ptr;
     let v = o.{}();
     if let Some(v) = v {{
         let s: *const c_char = v.as_ptr() as (*const c_char);
         set(p, s, to_c_int(v.len()));
     }}
 }}",
                 base,
                 o.name,
                 p.type_name(),
                 snake_case(name)
             )?;
             if p.write && p.type_name() == "QString" {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: *const c_ushort, len: c_int) {{
     let o = &mut *ptr;
     let mut s = String::new();
     set_string_from_utf16(&mut s, v, len);
     o.set_{}(Some(s));
 }}",
                     base,
                     o.name,
                     snake_case(name)
                 )?;
             } else if p.write {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: *const c_char, len: c_int) {{
     let o = &mut *ptr;
     let v = slice::from_raw_parts(v as *const u8, to_usize(len));
     o.set_{}(Some(v.into()));
 }}",
                     base,
                     o.name,
                     snake_case(name)
                 )?;
             }
         } else if p.optional {
             writeln!(
                 r,
                 "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(ptr: *const {}) -> COption<{}> {{
     match (&*ptr).{}() {{
         Some(value) => COption {{ data: value, some: true }},
         None => COption {{ data: {2}::default(), some: false}}
     }}
 }}",
                 base,
                 o.name,
                 p.property_type.rust_type(),
                 snake_case(name)
             )?;
             if p.write {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: {}) {{
     (&mut *ptr).set_{}(Some(v));
 }}",
                     base,
                     o.name,
                     p.property_type.rust_type(),
                     snake_case(name)
                 )?;
             }
         } else {
             writeln!(
                 r,
                 "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_get(ptr: *const {}) -> {} {{
     (&*ptr).{}()
 }}",
                 base,
                 o.name,
                 rust_type(p),
                 snake_case(name)
             )?;
             if p.write {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set(ptr: *mut {}, v: {}) {{
     (&mut *ptr).set_{}(v);
 }}",
                     base,
                     o.name,
                     rust_type(p),
                     snake_case(name)
                 )?;
             }
         }
         if p.write && p.optional {
             writeln!(
                 r,
                 "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set_none(ptr: *mut {}) {{
     let o = &mut *ptr;
     o.set_{}(None);
 }}",
                 base,
                 o.name,
                 snake_case(name)
             )?;
         }
     }
     for f in &o.functions {
         write_function(r, f, &lcname, o)?;
     }
     if o.object_type == ObjectType::List {
         writeln!(
             r,
             "
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_row_count(ptr: *const {0}) -> c_int {{
     to_c_int((&*ptr).row_count())
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_insert_rows(ptr: *mut {0}, row: c_int, count: c_int) -> bool {{
     (&mut *ptr).insert_rows(to_usize(row), to_usize(count))
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_remove_rows(ptr: *mut {0}, row: c_int, count: c_int) -> bool {{
     (&mut *ptr).remove_rows(to_usize(row), to_usize(count))
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_can_fetch_more(ptr: *const {0}) -> bool {{
     (&*ptr).can_fetch_more()
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_fetch_more(ptr: *mut {0}) {{
     (&mut *ptr).fetch_more()
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_sort(
     ptr: *mut {0},
     column: u8,
     order: SortOrder,
 ) {{
     (&mut *ptr).sort(column, order)
 }}",
             o.name, lcname
         )?;
     } else if o.object_type == ObjectType::Tree {
         writeln!(
             r,
             "
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_row_count(
     ptr: *const {0},
     index: COption<usize>,
 ) -> c_int {{
     to_c_int((&*ptr).row_count(index.into()))
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_can_fetch_more(
     ptr: *const {0},
     index: COption<usize>,
 ) -> bool {{
     (&*ptr).can_fetch_more(index.into())
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_fetch_more(ptr: *mut {0}, index: COption<usize>) {{
     (&mut *ptr).fetch_more(index.into())
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_sort(
     ptr: *mut {0},
     column: u8,
     order: SortOrder
 ) {{
     (&mut *ptr).sort(column, order)
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_check_row(
     ptr: *const {0},
     index: usize,
     row: c_int,
 ) -> COption<usize> {{
     (&*ptr).check_row(index.into(), to_usize(row)).into()
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_index(
     ptr: *const {0},
     index: COption<usize>,
     row: c_int,
 ) -> usize {{
     (&*ptr).index(index.into(), to_usize(row))
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_parent(ptr: *const {0}, index: usize) -> QModelIndex {{
     if let Some(parent) = (&*ptr).parent(index) {{
         QModelIndex {{
             row: to_c_int((&*ptr).row(parent)),
             internal_id: parent,
         }}
     }} else {{
         QModelIndex {{
             row: -1,
             internal_id: 0,
         }}
     }}
 }}
 #[no_mangle]
 pub unsafe extern \"C\" fn {1}_row(ptr: *const {0}, index: usize) -> c_int {{
     to_c_int((&*ptr).row(index))
 }}",
             o.name, lcname
         )?;
     }
     if o.object_type != ObjectType::Object {
         let (index_decl, index) = if o.object_type == ObjectType::Tree {
             (", index: usize", "index")
         } else {
             (", row: c_int", "to_usize(row)")
         };
         for (name, ip) in &o.item_properties {
             if ip.is_complex() && !ip.optional {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_data_{}(
     ptr: *const {}{},
     d: *mut {},
     set: fn(*mut {4}, *const c_char, len: c_int),
 ) {{
     let o = &*ptr;
     let data = o.{1}({});
     let s: *const c_char = data.as_ptr() as (*const c_char);
     set(d, s, to_c_int(data.len()));
 }}",
                     lcname,
                     snake_case(name),
                     o.name,
                     index_decl,
                     ip.type_name(),
                     index
                 )?;
             } else if ip.is_complex() {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_data_{}(
     ptr: *const {}{},
     d: *mut {},
     set: fn(*mut {4}, *const c_char, len: c_int),
 ) {{
     let o = &*ptr;
     let data = o.{1}({});
     if let Some(data) = data {{
         let s: *const c_char = data.as_ptr() as (*const c_char);
         set(d, s, to_c_int(data.len()));
     }}
 }}",
                     lcname,
                     snake_case(name),
                     o.name,
                     index_decl,
                     ip.type_name(),
                     index
                 )?;
             } else {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_data_{}(ptr: *const {}{}) -> {} {{
     let o = &*ptr;
     o.{1}({}).into()
 }}",
                     lcname,
                     snake_case(name),
                     o.name,
                     index_decl,
                     rust_c_type(ip),
                     index
                 )?;
             }
             if ip.write {
                 let val = if ip.optional { "Some(v)" } else { "v" };
                 if ip.type_name() == "QString" {
                     writeln!(
                         r,
                         "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set_data_{}(
     ptr: *mut {}{},
     s: *const c_ushort, len: c_int,
 ) -> bool {{
     let o = &mut *ptr;
     let mut v = String::new();
     set_string_from_utf16(&mut v, s, len);
     o.set_{1}({}, {})
 }}",
                         lcname,
                         snake_case(name),
                         o.name,
                         index_decl,
                         index,
                         val
                     )?;
                 } else if ip.type_name() == "QByteArray" {
                     writeln!(
                         r,
                         "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set_data_{}(
     ptr: *mut {}{},
     s: *const c_char, len: c_int,
 ) -> bool {{
     let o = &mut *ptr;
     let slice = ::std::slice::from_raw_parts(s as *const u8, to_usize(len));
     o.set_{1}({}, {})
 }}",
                         lcname,
                         snake_case(name),
                         o.name,
                         index_decl,
                         index,
                         if ip.optional { "Some(slice)" } else { "slice" }
                     )?;
                 } else {
                     let type_ = ip.item_property_type.rust_type();
                     writeln!(
                         r,
                         "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set_data_{}(
     ptr: *mut {}{},
     v: {},
 ) -> bool {{
     (&mut *ptr).set_{1}({}, {})
 }}",
                         lcname,
                         snake_case(name),
                         o.name,
                         index_decl,
                         type_,
                         index,
                         val
                     )?;
                 }
             }
             if ip.write && ip.optional {
                 writeln!(
                     r,
                     "
 #[no_mangle]
 pub unsafe extern \"C\" fn {}_set_data_{}_none(ptr: *mut {}{}) -> bool {{
     (&mut *ptr).set_{1}({}, None)
 }}",
                     lcname,
                     snake_case(name),
                     o.name,
                     index_decl,
                     index
                 )?;
             }
         }
     }
     Ok(())
 }
 
 fn write_rust_types(conf: &Config, r: &mut Vec<u8>) -> Result<()> {
     let mut has_option = false;
     let mut has_string = false;
     let mut has_byte_array = false;
     let mut has_list_or_tree = false;
 
     for o in conf.objects.values() {
         has_list_or_tree |= o.object_type != ObjectType::Object;
         for p in o.properties.values() {
             has_option |= p.optional;
             has_string |= p.property_type == Type::Simple(SimpleType::QString);
             has_byte_array |= p.property_type == Type::Simple(SimpleType::QByteArray);
         }
         for p in o.item_properties.values() {
             has_option |= p.optional;
             has_string |= p.item_property_type == SimpleType::QString;
             has_byte_array |= p.item_property_type == SimpleType::QByteArray;
         }
         for f in o.functions.values() {
             has_string |= f.return_type == SimpleType::QString;
             has_byte_array |= f.return_type == SimpleType::QByteArray;
             for a in &f.arguments {
                 has_string |= a.argument_type == SimpleType::QString;
                 has_byte_array |= a.argument_type == SimpleType::QByteArray;
             }
         }
     }
 
     if has_option || has_list_or_tree {
         writeln!(
             r,
             "
 
 #[repr(C)]
 pub struct COption<T> {{
     data: T,
     some: bool,
 }}
 
 impl<T> COption<T> {{
     #![allow(dead_code)]
     fn into(self) -> Option<T> {{
         if self.some {{
             Some(self.data)
         }} else {{
             None
         }}
     }}
 }}
 
 impl<T> From<Option<T>> for COption<T>
 where
     T: Default,
 {{
     fn from(t: Option<T>) -> COption<T> {{
         if let Some(v) = t {{
             COption {{
                 data: v,
                 some: true,
             }}
         }} else {{
             COption {{
                 data: T::default(),
                 some: false,
             }}
         }}
     }}
 }}"
         )?;
     }
     if has_string {
         writeln!(
             r,
             "
 
 pub enum QString {{}}
 
 fn set_string_from_utf16(s: &mut String, str: *const c_ushort, len: c_int) {{
     let utf16 = unsafe {{ slice::from_raw_parts(str, to_usize(len)) }};
     let characters = decode_utf16(utf16.iter().cloned())
         .map(|r| r.unwrap());
     s.clear();
     s.extend(characters);
 }}
 "
         )?;
     }
     if has_byte_array {
         writeln!(
             r,
             "
 
 pub enum QByteArray {{}}"
         )?;
     }
     if has_list_or_tree {
         writeln!(
             r,
             "
 
 #[repr(C)]
 #[derive(PartialEq, Eq, Debug)]
 pub enum SortOrder {{
     Ascending = 0,
     Descending = 1,
 }}
 
 #[repr(C)]
 pub struct QModelIndex {{
     row: c_int,
     internal_id: usize,
 }}"
         )?;
     }
 
     if has_string || has_byte_array || has_list_or_tree {
         writeln!(
             r,
             "
 
 fn to_usize(n: c_int) -> usize {{
     if n < 0 {{
         panic!(\"Cannot cast {{}} to usize\", n);
     }}
     n as usize
 }}
 "
         )?;
     }
 
     if has_string || has_byte_array || has_list_or_tree {
         writeln!(
             r,
             "
 fn to_c_int(n: usize) -> c_int {{
     if n > c_int::max_value() as usize {{
         panic!(\"Cannot cast {{}} to c_int\", n);
     }}
     n as c_int
 }}
 "
         )?;
     }
     Ok(())
 }
 
 pub fn write_interface(conf: &Config) -> Result<()> {
     let mut r = Vec::new();
     writeln!(
         r,
         "/* generated by rust_qt_binding_generator */
 #![allow(unknown_lints)]
 #![allow(mutex_atomic, needless_pass_by_value)]
 use libc::{{c_char, c_ushort, c_int}};
 use std::slice;
 use std::char::decode_utf16;
 
 use std::sync::{{Arc, Mutex}};
 use std::ptr::null;
 
 use {}::*;",
         conf.rust.implementation_module
     )?;
 
     write_rust_types(conf, &mut r)?;
 
     for object in conf.objects.values() {
         write_rust_interface_object(&mut r, object, conf)?;
     }
     let mut file = conf
         .config_file
         .parent()
         .unwrap()
         .join(&conf.rust.dir)
         .join("src")
         .join(&conf.rust.interface_module);
     file.set_extension("rs");
     write_if_different(file, &r)
 }
 
 fn write_rust_implementation_object(r: &mut Vec<u8>, o: &Object) -> Result<()> {
     if o.object_type != ObjectType::Object {
         writeln!(r, "#[derive(Default, Clone)]")?;
         writeln!(r, "struct {}Item {{", o.name)?;
         for (name, ip) in &o.item_properties {
             let lc = snake_case(name);
             if ip.optional {
                 writeln!(
                     r,
                     "    {}: Option<{}>,",
                     lc,
                     ip.item_property_type.rust_type()
                 )?;
             } else {
                 writeln!(r, "    {}: {},", lc, ip.item_property_type.rust_type())?;
             }
         }
         writeln!(r, "}}\n")?;
     }
     let mut model_struct = String::new();
     writeln!(r, "pub struct {} {{\n    emit: {0}Emitter,", o.name)?;
     if o.object_type == ObjectType::List {
         model_struct = format!(", model: {}List", o.name);
         writeln!(r, "    model: {}List,", o.name)?;
     } else if o.object_type == ObjectType::Tree {
         model_struct = format!(", model: {}Tree", o.name);
         writeln!(r, "    model: {}Tree,", o.name)?;
     }
     for (name, p) in &o.properties {
         let lc = snake_case(name);
         writeln!(r, "    {}: {},", lc, rust_type(p))?;
     }
     if o.object_type != ObjectType::Object {
         writeln!(r, "    list: Vec<{}Item>,", o.name)?;
     }
     writeln!(r, "}}\n")?;
     for (name, p) in &o.properties {
         if p.is_object() {
             model_struct += &format!(", {}: {}", name, p.type_name());
         }
     }
     writeln!(
         r,
         "impl {}Trait for {0} {{
     fn new(emit: {0}Emitter{}) -> {0} {{
         {0} {{
             emit,",
         o.name, model_struct
     )?;
     if o.object_type != ObjectType::Object {
         writeln!(r, "            model,")?;
         writeln!(r, "            list: Vec::new(),")?;
     }
     for (name, p) in &o.properties {
         let lc = snake_case(name);
         if p.is_object() {
             writeln!(r, "            {},", lc)?;
         } else {
             writeln!(r, "            {}: {},", lc, rust_type_init(p))?;
         }
     }
     writeln!(
         r,
         "        }}
     }}
     fn emit(&self) -> &{}Emitter {{
         &self.emit
     }}",
         o.name
     )?;
     for (name, p) in &o.properties {
         let lc = snake_case(name);
         if p.is_object() {
             writeln!(
                 r,
                 "    fn {}(&self) -> &{} {{
         &self.{0}
     }}
     fn {0}_mut(&mut self) -> &mut {1} {{
         &mut self.{0}
     }}",
                 lc,
                 rust_return_type(p)
             )?;
         } else if p.rust_by_function {
             writeln!(
                 r,
                 "    fn {}<F>(&self, getter: F)
     where
         F: FnOnce({}),
     {{
         getter(&self.{0})
     }}",
                 lc,
                 rust_return_type(p)
             )?;
         } else {
             writeln!(r, "    fn {}(&self) -> {} {{", lc, rust_return_type(p))?;
             if p.is_complex() {
                 if p.optional {
                     writeln!(r, "        self.{}.as_ref().map(|p| &p[..])", lc)?;
                 } else {
                     writeln!(r, "        &self.{}", lc)?;
                 }
             } else {
                 writeln!(r, "        self.{}", lc)?;
             }
             writeln!(r, "    }}")?;
         }
         if !p.is_object() && p.write {
             let bytearray = p.property_type == Type::Simple(SimpleType::QByteArray);
             let (t, v) = if bytearray && p.optional {
                 ("Option<&[u8]>".to_string(), ".map(|v| v.to_vec())")
             } else if bytearray {
                 ("&[u8]".to_string(), ".to_vec()")
             } else {
                 (rust_type(p), "")
             };
             writeln!(
                 r,
                 "    fn set_{}(&mut self, value: {}) {{
         self.{0} = value{};
         self.emit.{0}_changed();
     }}",
                 lc, t, v
             )?;
         }
     }
     if o.object_type == ObjectType::List {
         writeln!(
             r,
             "    fn row_count(&self) -> usize {{\n        self.list.len()\n    }}"
         )?;
     } else if o.object_type == ObjectType::Tree {
         writeln!(
             r,
             "    fn row_count(&self, item: Option<usize>) -> usize {{
         self.list.len()
     }}
     fn index(&self, item: Option<usize>, row: usize) -> usize {{
         0
     }}
     fn parent(&self, index: usize) -> Option<usize> {{
         None
     }}
     fn row(&self, index: usize) -> usize {{
         index
     }}
     fn check_row(&self, index: usize, _row: usize) -> Option<usize> {{
         if index < self.list.len() {{
             Some(index)
         }} else {{
             None
         }}
     }}"
         )?;
     }
     if o.object_type != ObjectType::Object {
         for (name, ip) in &o.item_properties {
             let lc = snake_case(name);
             writeln!(
                 r,
                 "    fn {}(&self, index: usize) -> {} {{",
                 lc,
                 rust_return_type_(ip)
             )?;
             if ip.is_complex() && ip.optional {
                 writeln!(
                     r,
                     "        self.list[index].{}.as_ref().map(|v| &v[..])",
                     lc
                 )?;
             } else if ip.is_complex() {
                 writeln!(r, "        &self.list[index].{}", lc)?;
             } else {
                 writeln!(r, "        self.list[index].{}", lc)?;
             }
             writeln!(r, "    }}")?;
             let bytearray = ip.item_property_type == SimpleType::QByteArray;
             if ip.write && bytearray && ip.optional {
                 writeln!(
                     r,
                     "    fn set_{}(&mut self, index: usize, v: Option<&[u8]>) -> bool {{
         self.list[index].{0} = v.map(|v| v.to_vec());
         true
     }}",
                     lc
                 )?;
             } else if ip.write && bytearray {
                 writeln!(
                     r,
                     "    fn set_{}(&mut self, index: usize, v: &[u8]) -> bool {{
         self.list[index].{0} = v.to_vec();
         true
     }}",
                     lc
                 )?;
             } else if ip.write {
                 writeln!(
                     r,
                     "    fn set_{}(&mut self, index: usize, v: {}) -> bool {{
         self.list[index].{0} = v;
         true
     }}",
                     lc,
                     rust_type_(ip)
                 )?;
             }
         }
     }
     writeln!(r, "}}")
 }
 
 pub fn write_implementation(conf: &Config) -> Result<()> {
     let mut file = conf
         .config_file
         .parent()
         .unwrap()
         .join(&conf.rust.dir)
         .join("src")
         .join(&conf.rust.implementation_module);
+    if !conf.overwrite_implementation && file.exists() {
+        return Ok(());
+    }
     file.set_extension("rs");
     if !conf.overwrite_implementation && file.exists() {
         return Ok(());
     }
     let mut r = Vec::new();
     writeln!(
         r,
         "#![allow(unused_imports)]
 #![allow(unused_variables)]
 #![allow(dead_code)]
 use {}::*;
 ",
         conf.rust.interface_module
     )?;
 
     for object in conf.objects.values() {
         write_rust_implementation_object(&mut r, object)?;
     }
     write_if_different(file, &r)
 }