diff --git a/README.md b/README.md
index 3d6d1e5..c9a5785 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,87 @@
-# Rust Qt Bindings Generator
+# Rust Qt Binding Generator
 
-![Rust Qt Bindings](logo.svg)
+![Rust Qt Binding](logo.svg)
 
-This generator gets you started quickly to use Rust code from Qt and QML.
+This code generator gets you started quickly to use Rust code from Qt and QML. In other words, it helps to create a Qt based GUI on top of Rust code.
+
+Qt is a mature cross-platform graphical user interface library. Rust is a new programming language with strong compile time checks and a modern syntax.
+
+To combine Qt and Rust, write an interface in a JSON file. From that, the generator creates Qt code and Rust code. The Qt code can be used directly. The Rust code has two files: interface and implementation. The interface can be used directly.
+
+```json
+{
+    "cppFile": "src/person.cpp",
+    "rust": {
+        "dir": "rust",
+        "interfaceModule": "interface",
+        "implementationModule": "implementation"
+    },
+    "objects": {
+        "Person": {
+            "type": "Object",
+            "properties": {
+                "name": {
+                    "type": "QString",
+                    "write": true
+                }
+            }
+        }
+    }
+}
+```
+
+This file describes an binding with one object, `Person`. `Person` has one property: `name`. It is a writable property.
+
+The Rust Qt Binding Generator will create binding source code from this description:
+
+```bash
+rust_qt_binding_generator binding.json
+```
+
+This will create four files:
+
+* *src/person.h*
+* *src/person.cpp*
+* rust/src/implemenation.rs
+* *rust/src/interface.rs*
+
+Only `implementation.rs` should be changed. The other files are the binding. `implementation.rs` is initialy created with a simple implementation that is shown here with some comments.
+
+```rust
+use interface::*;
+
+/// A Person
+pub struct Person {
+    /// Emit signals  the the Qt code.
+    emit: PersonEmitter,
+    /// The name of the person.
+    name: String,
+}
+
+/// Implementation of the binding
+impl PersonTrait for Person {
+    /// Create a new person with default data.
+    fn create(emit: PersonEmitter) -> Person {
+        Person {
+            emit: emit,
+            name: String::new(),
+        }
+    }
+    /// The emitter can emit signals to the Qt code.
+    fn emit(&self) -> &PersonEmitter {
+        &self.emit
+    }
+    /// Get the name of the Person
+    fn get_name(&self) -> String {
+        self.name.clone()
+    }
+    /// Set the name of the Person
+    fn set_name(&mut self, value: String) {
+        self.name = value;
+        self.emit.name_changed();
+    }
+}
+```
 
 The building block of Qt and QML projects are QObject and the Model View classes. `rust_qt_binding_generator` reads a json file to generate QObject or QAbstractItemModel classes that call into generated Rust files. For each type from the JSON file, a Rust trait is generated that should be implemented.
 
diff --git a/demo/processes.json b/demo/processes.json
index 59cdc6c..ee2c816 100644
--- a/demo/processes.json
+++ b/demo/processes.json
@@ -38,7 +38,8 @@
                     "type": "quint8"
                 },
                 "cmd": {
-                    "type": "QString"
+                    "type": "QString",
+                    "rustByValue": true
                 }
             }
         }
diff --git a/demo/rust/src/implementation.rs b/demo/rust/src/implementation.rs
index 52d17a9..774e939 100644
--- a/demo/rust/src/implementation.rs
+++ b/demo/rust/src/implementation.rs
@@ -13,6 +13,7 @@ pub struct DirEntry {
     name: OsString,
     metadata: Option<Metadata>,
     path: Option<PathBuf>,
+    icon: Vec<u8>,
 }
 
 type Incoming<T> = Arc<Mutex<HashMap<usize, Vec<T>>>>;
@@ -23,6 +24,7 @@ impl Item for DirEntry {
             name: OsString::from(name),
             metadata: metadata(name).ok(),
             path: None,
+            icon: Vec::new()
         }
     }
     fn can_fetch_more(&self) -> bool {
@@ -43,6 +45,9 @@ impl Item for DirEntry {
     fn file_size(&self) -> Option<u64> {
         self.metadata.as_ref().map(|m| m.len())
     }
+    fn icon(&self) -> &[u8] {
+        &self.icon
+    }
     fn retrieve(id: usize, parents: Vec<&DirEntry>, q: Incoming<Self>, emit: TreeEmitter) {
         let mut v = Vec::new();
         let path: PathBuf = parents.into_iter().map(|e| &e.name).collect();
@@ -53,6 +58,7 @@ impl Item for DirEntry {
                         name: i.file_name(),
                         metadata: i.metadata().ok(),
                         path: Some(i.path()),
+                        icon: Vec::new(),
                     };
                     v.push(de);
                 }
@@ -73,6 +79,7 @@ impl Default for DirEntry {
             name: OsString::new(),
             metadata: None,
             path: None,
+            icon: Vec::new(),
         }
     }
 }
@@ -86,6 +93,7 @@ pub trait Item: Default {
     fn file_permissions(&self) -> i32;
     fn file_type(&self) -> i32;
     fn file_size(&self) -> Option<u64>;
+    fn icon(&self) -> &[u8];
 }
 
 pub type Tree = RGeneralItemModel<DirEntry>;
@@ -195,8 +203,8 @@ where
     fn emit(&self) -> &TreeEmitter {
         &self.emit
     }
-    fn get_path(&self) -> Option<String> {
-        self.path.clone()
+    fn get_path(&self) -> Option<&str> {
+        self.path.as_ref().map(|s|&s[..])
     }
     fn set_path(&mut self, value: Option<String>) {
         if self.path != value {
@@ -261,8 +269,8 @@ where
         self.get(item).data.file_permissions()
     }
     #[allow(unused_variables)]
-    fn file_icon(&self, item: usize) -> Vec<u8> {
-        Vec::new()
+    fn file_icon(&self, item: usize) -> &[u8] {
+        self.get(item).data.icon()
     }
     fn file_path(&self, item: usize) -> Option<String> {
         self.get(item).data.file_path()
diff --git a/demo/rust/src/interface.rs b/demo/rust/src/interface.rs
index 74316f2..53fb74c 100644
--- a/demo/rust/src/interface.rs
+++ b/demo/rust/src/interface.rs
@@ -55,6 +55,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -78,8 +87,8 @@ impl QByteArray {
     }
 }
 
-impl<'a> From<&'a Vec<u8>> for QByteArray {
-    fn from(value: &'a Vec<u8>) -> QByteArray {
+impl<'a> From<&'a [u8]> for QByteArray {
+    fn from(value: &'a [u8]) -> QByteArray {
         QByteArray {
             len: value.len() as c_int,
             data: value.as_ptr(),
@@ -167,7 +176,7 @@ impl TreeUniformTree {
 pub trait TreeTrait {
     fn create(emit: TreeEmitter, model: TreeUniformTree) -> Self;
     fn emit(&self) -> &TreeEmitter;
-    fn get_path(&self) -> Option<String>;
+    fn get_path(&self) -> Option<&str>;
     fn set_path(&mut self, value: Option<String>);
     fn row_count(&self, Option<usize>) -> usize;
     fn can_fetch_more(&self, Option<usize>) -> bool {
@@ -178,7 +187,7 @@ pub trait TreeTrait {
     fn index(&self, item: Option<usize>, row: usize) -> usize;
     fn parent(&self, item: usize) -> Option<usize>;
     fn row(&self, item: usize) -> usize;
-    fn file_icon(&self, item: usize) -> Vec<u8>;
+    fn file_icon(&self, item: usize) -> &[u8];
     fn file_name(&self, item: usize) -> String;
     fn file_path(&self, item: usize) -> Option<String>;
     fn file_permissions(&self, item: usize) -> i32;
@@ -231,7 +240,7 @@ pub unsafe extern "C" fn tree_path_get(
 ) {
     let data = (&*ptr).get_path();
     if let Some(data) = data {
-        set(p, QString::from(&data));
+        set(p, data.into());
     }
 }
 
@@ -323,7 +332,7 @@ pub unsafe extern "C" fn tree_data_file_icon(
     set: fn(*mut c_void, QByteArray),
 ) {
     let data = (&*ptr).file_icon(item);
-    set(d, QByteArray::from(&data));
+    set(d, (data).into());
 }
 
 #[no_mangle]
@@ -333,7 +342,7 @@ pub unsafe extern "C" fn tree_data_file_name(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).file_name(item);
-    set(d, QString::from(&data));
+    set(d, (&data).into());
 }
 
 #[no_mangle]
diff --git a/demo/rust/src/processes_implementation.rs b/demo/rust/src/processes_implementation.rs
index 4ad75cb..ac1ca88 100644
--- a/demo/rust/src/processes_implementation.rs
+++ b/demo/rust/src/processes_implementation.rs
@@ -361,8 +361,8 @@ impl ProcessesTrait for Processes {
     fn memory(&self, item: usize) -> u64 {
         self.process(item).memory
     }
-    fn name(&self, item: usize) -> String {
-        self.process(item).name.clone()
+    fn name(&self, item: usize) -> &str {
+        &self.process(item).name
     }
     fn cmd(&self, item: usize) -> String {
         self.process(item).cmd.join(" ")
diff --git a/demo/rust/src/processes_interface.rs b/demo/rust/src/processes_interface.rs
index ae4e35a..eb90df9 100644
--- a/demo/rust/src/processes_interface.rs
+++ b/demo/rust/src/processes_interface.rs
@@ -55,6 +55,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -159,7 +168,7 @@ pub trait ProcessesTrait {
     fn cpu_percentage(&self, item: usize) -> u8;
     fn cpu_usage(&self, item: usize) -> f32;
     fn memory(&self, item: usize) -> u64;
-    fn name(&self, item: usize) -> String;
+    fn name(&self, item: usize) -> &str;
     fn pid(&self, item: usize) -> u32;
     fn uid(&self, item: usize) -> u32;
 }
@@ -290,7 +299,7 @@ pub unsafe extern "C" fn processes_data_cmd(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).cmd(item);
-    set(d, QString::from(&data));
+    set(d, (&data).into());
 }
 
 #[no_mangle]
@@ -315,7 +324,7 @@ pub unsafe extern "C" fn processes_data_name(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).name(item);
-    set(d, QString::from(&data));
+    set(d, (data).into());
 }
 
 #[no_mangle]
diff --git a/demo/tree.json b/demo/tree.json
index e5db5f6..0085cdc 100644
--- a/demo/tree.json
+++ b/demo/tree.json
@@ -18,7 +18,8 @@
             "itemProperties": {
                 "fileName": {
                     "type": "QString",
-                    "roles": [ ["display"] ]
+                    "roles": [ ["display"] ],
+                    "rustByValue": true
                 },
                 "fileIcon": {
                     "type": "QByteArray",
@@ -32,7 +33,8 @@
                 "filePath": {
                     "type": "QString",
                     "optional": true,
-                    "roles": [ [], [], ["display"] ]
+                    "roles": [ [], [], ["display"] ],
+                    "rustByValue": true
                 },
                 "filePermissions": {
                     "type": "qint32",
diff --git a/src/parseJson.cpp b/src/parseJson.cpp
index 5141099..2b56420 100644
--- a/src/parseJson.cpp
+++ b/src/parseJson.cpp
@@ -12,7 +12,7 @@ BindingTypeProperties simpleType(BindingType type, const char* name, const char*
         .cppSetType = name,
         .cSetType = name,
         .rustType = name,
-        .rustTypeInit = init,
+        .rustTypeInit = init
     };
 }
 
@@ -105,6 +105,7 @@ parseProperty(const QString& name, const QJsonObject& json) {
     p.type = parseBindingType(json.value("type").toString());
     p.write = json.value("write").toBool();
     p.optional = json.value("optional").toBool();
+    p.rustByValue = json.value("rustByValue").toBool();
     return p;
 }
 
@@ -129,6 +130,7 @@ parseItemProperty(const QString& name, const QJsonObject& json) {
     ip.type = parseBindingType(json.value("type").toString());
     ip.write = json.value("write").toBool();
     ip.optional = json.value("optional").toBool();
+    ip.rustByValue = json.value("rustByValue").toBool();
     QJsonArray roles = json.value("roles").toArray();
     for (auto r: roles) {
         QList<Qt::ItemDataRole> l;
diff --git a/src/rust.cpp b/src/rust.cpp
index 0355f0c..daa9ed2 100644
--- a/src/rust.cpp
+++ b/src/rust.cpp
@@ -10,6 +10,25 @@ QString rustType(const T& p)
     return p.type.rustType;
 }
 
+template <typename T>
+QString rustReturnType(const T& p)
+{
+    QString type = p.type.rustType;
+    if (type == "String" && !p.rustByValue) {
+        type = "str";
+    }
+    if (type == "Vec<u8>" && !p.rustByValue) {
+        type = "[u8]";
+    }
+    if (p.type.isComplex() && !p.rustByValue) {
+        type = "&" + type;
+    }
+    if (p.optional) {
+        return "Option<" + type + ">";
+    }
+    return type;
+}
+
 template <typename T>
 QString rustCType(const T& p)
 {
@@ -235,7 +254,7 @@ pub trait %1Trait {
             r << QString("    fn get_%1(&self) -> &%2;\n").arg(lc, rustType(p));
             r << QString("    fn get_mut_%1(&mut self) -> &mut %2;\n").arg(lc, rustType(p));
         } else {
-            r << QString("    fn get_%1(&self) -> %2;\n").arg(lc, rustType(p));
+            r << QString("    fn get_%1(&self) -> %2;\n").arg(lc, rustReturnType(p));
             if (p.write) {
                 r << QString("    fn set_%1(&mut self, value: %2);\n").arg(lc, rustType(p));
             }
@@ -264,7 +283,7 @@ pub trait %1Trait {
     if (o.type != ObjectType::Object) {
         for (auto ip: o.itemProperties) {
             r << QString("    fn %1(&self, item: usize) -> %2;\n")
-                    .arg(snakeCase(ip.name), rustType(ip));
+                    .arg(snakeCase(ip.name), rustReturnType(ip));
             if (ip.write) {
                 r << QString("    fn set_%1(&mut self, item: usize, %2) -> bool;\n")
                     .arg(snakeCase(ip.name), rustType(ip));
@@ -308,9 +327,10 @@ pub unsafe extern "C" fn %2_get(
     set: fn(*mut c_void, %4),
 ) {
     let data = (&*ptr).get_%3();
-    set(p, %4::from(&data));
+    set(p, %5data.into());
 }
-)").arg(o.name, base, snakeCase(p.name), p.type.name);
+)").arg(o.name, base, snakeCase(p.name), p.type.name,
+                p.rustByValue ?"&" :"");
             if (p.write) {
                 const QString type = p.type.name == "QString" ? "QStringIn" : p.type.name;
                 r << QString(R"(
@@ -330,10 +350,11 @@ pub unsafe extern "C" fn %2_get(
 ) {
     let data = (&*ptr).get_%3();
     if let Some(data) = data {
-        set(p, %4::from(&data));
+        set(p, %5data.into());
     }
 }
-)").arg(o.name, base, snakeCase(p.name), p.type.name);
+)").arg(o.name, base, snakeCase(p.name), p.type.name,
+                p.rustByValue ?"&" :"");
             if (p.write) {
                 const QString type = p.type.name == "QString" ? "QStringIn" : p.type.name;
                 r << QString(R"(
@@ -479,9 +500,10 @@ pub unsafe extern "C" fn %2_data_%3(
     set: fn(*mut c_void, %4),
 ) {
     let data = (&*ptr).%3(%6);
-    set(d, %4::from(&data));
+    set(d, (%7data).into());
 }
-)").arg(o.name, lcname, snakeCase(ip.name), ip.type.name, indexDecl, index);
+)").arg(o.name, lcname, snakeCase(ip.name), ip.type.name, indexDecl, index,
+                ip.rustByValue ?"&" :"");
             } else if (ip.type.isComplex()) {
                 r << QString(R"(
 #[no_mangle]
@@ -616,6 +638,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -642,8 +673,8 @@ impl QByteArray {
     }
 }
 
-impl<'a> From<&'a Vec<u8>> for QByteArray {
-    fn from(value: &'a Vec<u8>) -> QByteArray {
+impl<'a> From<&'a [u8]> for QByteArray {
+    fn from(value: &'a [u8]) -> QByteArray {
         QByteArray {
             len: value.len() as c_int,
             data: value.as_ptr(),
@@ -760,11 +791,21 @@ void writeRustImplementationObject(QTextStream& r, const Object& o) {
     fn get_mut_%1(&mut self) -> &mut %2 {
         &mut self.%1
     }
-)").arg(lc, rustType(p));
+)").arg(lc, rustReturnType(p));
         } else {
-            r << QString("    fn get_%1(&self) -> %2 {\n").arg(lc, rustType(p));
+            r << QString("    fn get_%1(&self) -> %2 {\n").arg(lc, rustReturnType(p));
             if (p.type.isComplex()) {
-                r << QString("        self.%1.clone()\n").arg(lc);
+                if (p.optional) {
+/*
+                    if (rustType(p) == "Option<String>") {
+                        r << QString("        self.%1.as_ref().map(|p|p.as_str())\n").arg(lc);
+                    } else {
+                    }
+*/
+                    r << QString("        self.%1.as_ref().map(|p|&p[..])\n").arg(lc);
+                } else {
+                    r << QString("        &self.%1\n").arg(lc);
+                }
             } else {
                 r << QString("        self.%1\n").arg(lc);
             }
@@ -803,8 +844,12 @@ void writeRustImplementationObject(QTextStream& r, const Object& o) {
         for (auto ip: o.itemProperties) {
             const QString lc(snakeCase(ip.name));
             r << QString("    fn %1(&self, item: usize) -> %2 {\n")
-                    .arg(lc, rustType(ip));
-            r << "        self.list[item]." << lc << ".clone()\n";
+                    .arg(lc, rustReturnType(ip));
+            if (ip.type.isComplex()) {
+                r << "        &self.list[item]." << lc << "\n";
+            } else {
+                r << "        self.list[item]." << lc << "\n";
+            }
             r << "    }\n";
             if (ip.write) {
                 r << QString("    fn set_%1(&mut self, item: usize, v: %2) -> bool {\n")
diff --git a/src/structs.h b/src/structs.h
index ded3783..80c4d34 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -41,6 +41,7 @@ struct Property {
     BindingTypeProperties type;
     bool write;
     bool optional;
+    bool rustByValue;
 };
 
 struct ItemProperty {
@@ -48,6 +49,7 @@ struct ItemProperty {
     BindingTypeProperties type;
     bool write;
     bool optional;
+    bool rustByValue;
     QList<QList<Qt::ItemDataRole>> roles;
 };
 
diff --git a/tests/rust_list/src/implementation.rs b/tests/rust_list/src/implementation.rs
index 2ea08d8..867b8a2 100644
--- a/tests/rust_list/src/implementation.rs
+++ b/tests/rust_list/src/implementation.rs
@@ -28,8 +28,8 @@ impl PersonsTrait for Persons {
     fn row_count(&self) -> usize {
         self.list.len()
     }
-    fn user_name(&self, item: usize) -> String {
-        self.list[item].user_name.clone()
+    fn user_name(&self, item: usize) -> &str {
+        &self.list[item].user_name
     }
     fn set_user_name(&mut self, item: usize, v: String) -> bool {
         self.list[item].user_name = v;
diff --git a/tests/rust_list/src/interface.rs b/tests/rust_list/src/interface.rs
index 147f231..81b85a7 100644
--- a/tests/rust_list/src/interface.rs
+++ b/tests/rust_list/src/interface.rs
@@ -55,6 +55,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -143,7 +152,7 @@ pub trait PersonsTrait {
     }
     fn fetch_more(&mut self) {}
     fn sort(&mut self, u8, SortOrder) {}
-    fn user_name(&self, item: usize) -> String;
+    fn user_name(&self, item: usize) -> &str;
     fn set_user_name(&mut self, item: usize, String) -> bool;
 }
 
@@ -210,7 +219,7 @@ pub unsafe extern "C" fn persons_data_user_name(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).user_name(row as usize);
-    set(d, QString::from(&data));
+    set(d, (data).into());
 }
 
 #[no_mangle]
diff --git a/tests/rust_object/src/implementation.rs b/tests/rust_object/src/implementation.rs
index 867f7fe..7880813 100644
--- a/tests/rust_object/src/implementation.rs
+++ b/tests/rust_object/src/implementation.rs
@@ -18,8 +18,8 @@ impl PersonTrait for Person {
     fn emit(&self) -> &PersonEmitter {
         &self.emit
     }
-    fn get_user_name(&self) -> String {
-        self.user_name.clone()
+    fn get_user_name(&self) -> &str {
+        &self.user_name
     }
     fn set_user_name(&mut self, value: String) {
         self.user_name = value;
diff --git a/tests/rust_object/src/interface.rs b/tests/rust_object/src/interface.rs
index e5b9fb1..1642eb6 100644
--- a/tests/rust_object/src/interface.rs
+++ b/tests/rust_object/src/interface.rs
@@ -29,6 +29,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -63,7 +72,7 @@ impl PersonEmitter {
 pub trait PersonTrait {
     fn create(emit: PersonEmitter) -> Self;
     fn emit(&self) -> &PersonEmitter;
-    fn get_user_name(&self) -> String;
+    fn get_user_name(&self) -> &str;
     fn set_user_name(&mut self, value: String);
 }
 
@@ -92,7 +101,7 @@ pub unsafe extern "C" fn person_user_name_get(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).get_user_name();
-    set(p, QString::from(&data));
+    set(p, data.into());
 }
 
 #[no_mangle]
diff --git a/tests/rust_object_types/src/implementation.rs b/tests/rust_object_types/src/implementation.rs
index d5cc0ae..d64d07c 100644
--- a/tests/rust_object_types/src/implementation.rs
+++ b/tests/rust_object_types/src/implementation.rs
@@ -39,8 +39,8 @@ impl ObjectTrait for Object {
         self.boolean = value;
         self.emit.boolean_changed();
     }
-    fn get_bytearray(&self) -> Vec<u8> {
-        self.bytearray.clone()
+    fn get_bytearray(&self) -> &[u8] {
+        &self.bytearray
     }
     fn set_bytearray(&mut self, value: Vec<u8>) {
         self.bytearray = value;
@@ -53,22 +53,22 @@ impl ObjectTrait for Object {
         self.integer = value;
         self.emit.integer_changed();
     }
-    fn get_optional_bytearray(&self) -> Option<Vec<u8>> {
-        self.optional_bytearray.clone()
+    fn get_optional_bytearray(&self) -> Option<&[u8]> {
+        self.optional_bytearray.as_ref().map(|p|&p[..])
     }
     fn set_optional_bytearray(&mut self, value: Option<Vec<u8>>) {
         self.optional_bytearray = value;
         self.emit.optional_bytearray_changed();
     }
-    fn get_optional_string(&self) -> Option<String> {
-        self.optional_string.clone()
+    fn get_optional_string(&self) -> Option<&str> {
+        self.optional_string.as_ref().map(|p|&p[..])
     }
     fn set_optional_string(&mut self, value: Option<String>) {
         self.optional_string = value;
         self.emit.optional_string_changed();
     }
-    fn get_string(&self) -> String {
-        self.string.clone()
+    fn get_string(&self) -> &str {
+        &self.string
     }
     fn set_string(&mut self, value: String) {
         self.string = value;
diff --git a/tests/rust_object_types/src/interface.rs b/tests/rust_object_types/src/interface.rs
index 9e42e87..989899b 100644
--- a/tests/rust_object_types/src/interface.rs
+++ b/tests/rust_object_types/src/interface.rs
@@ -55,6 +55,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -78,8 +87,8 @@ impl QByteArray {
     }
 }
 
-impl<'a> From<&'a Vec<u8>> for QByteArray {
-    fn from(value: &'a Vec<u8>) -> QByteArray {
+impl<'a> From<&'a [u8]> for QByteArray {
+    fn from(value: &'a [u8]) -> QByteArray {
         QByteArray {
             len: value.len() as c_int,
             data: value.as_ptr(),
@@ -163,15 +172,15 @@ pub trait ObjectTrait {
     fn emit(&self) -> &ObjectEmitter;
     fn get_boolean(&self) -> bool;
     fn set_boolean(&mut self, value: bool);
-    fn get_bytearray(&self) -> Vec<u8>;
+    fn get_bytearray(&self) -> &[u8];
     fn set_bytearray(&mut self, value: Vec<u8>);
     fn get_integer(&self) -> i32;
     fn set_integer(&mut self, value: i32);
-    fn get_optional_bytearray(&self) -> Option<Vec<u8>>;
+    fn get_optional_bytearray(&self) -> Option<&[u8]>;
     fn set_optional_bytearray(&mut self, value: Option<Vec<u8>>);
-    fn get_optional_string(&self) -> Option<String>;
+    fn get_optional_string(&self) -> Option<&str>;
     fn set_optional_string(&mut self, value: Option<String>);
-    fn get_string(&self) -> String;
+    fn get_string(&self) -> &str;
     fn set_string(&mut self, value: String);
     fn get_u64(&self) -> u64;
     fn set_u64(&mut self, value: u64);
@@ -228,7 +237,7 @@ pub unsafe extern "C" fn object_bytearray_get(
     set: fn(*mut c_void, QByteArray),
 ) {
     let data = (&*ptr).get_bytearray();
-    set(p, QByteArray::from(&data));
+    set(p, data.into());
 }
 
 #[no_mangle]
@@ -254,7 +263,7 @@ pub unsafe extern "C" fn object_optional_bytearray_get(
 ) {
     let data = (&*ptr).get_optional_bytearray();
     if let Some(data) = data {
-        set(p, QByteArray::from(&data));
+        set(p, data.into());
     }
 }
 
@@ -275,7 +284,7 @@ pub unsafe extern "C" fn object_optional_string_get(
 ) {
     let data = (&*ptr).get_optional_string();
     if let Some(data) = data {
-        set(p, QString::from(&data));
+        set(p, data.into());
     }
 }
 
@@ -295,7 +304,7 @@ pub unsafe extern "C" fn object_string_get(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).get_string();
-    set(p, QString::from(&data));
+    set(p, data.into());
 }
 
 #[no_mangle]
diff --git a/tests/rust_objects/src/implementation.rs b/tests/rust_objects/src/implementation.rs
index c4f1035..d3186d4 100644
--- a/tests/rust_objects/src/implementation.rs
+++ b/tests/rust_objects/src/implementation.rs
@@ -41,8 +41,8 @@ impl InnerObjectTrait for InnerObject {
     fn emit(&self) -> &InnerObjectEmitter {
         &self.emit
     }
-    fn get_description(&self) -> String {
-        self.description.clone()
+    fn get_description(&self) -> &str {
+        &self.description
     }
     fn set_description(&mut self, value: String) {
         self.description = value;
diff --git a/tests/rust_objects/src/interface.rs b/tests/rust_objects/src/interface.rs
index 15bfcd4..5dd9bdf 100644
--- a/tests/rust_objects/src/interface.rs
+++ b/tests/rust_objects/src/interface.rs
@@ -29,6 +29,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -121,7 +130,7 @@ impl InnerObjectEmitter {
 pub trait InnerObjectTrait {
     fn create(emit: InnerObjectEmitter) -> Self;
     fn emit(&self) -> &InnerObjectEmitter;
-    fn get_description(&self) -> String;
+    fn get_description(&self) -> &str;
     fn set_description(&mut self, value: String);
 }
 
@@ -150,7 +159,7 @@ pub unsafe extern "C" fn inner_object_description_get(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).get_description();
-    set(p, QString::from(&data));
+    set(p, data.into());
 }
 
 #[no_mangle]
diff --git a/tests/rust_tree/src/implementation.rs b/tests/rust_tree/src/implementation.rs
index 5cacf1a..0c1c3e9 100644
--- a/tests/rust_tree/src/implementation.rs
+++ b/tests/rust_tree/src/implementation.rs
@@ -37,8 +37,8 @@ impl PersonsTrait for Persons {
     fn row(&self, item: usize) -> usize {
         item
     }
-    fn user_name(&self, item: usize) -> String {
-        self.list[item].user_name.clone()
+    fn user_name(&self, item: usize) -> &str {
+        &self.list[item].user_name
     }
     fn set_user_name(&mut self, item: usize, v: String) -> bool {
         self.list[item].user_name = v;
diff --git a/tests/rust_tree/src/interface.rs b/tests/rust_tree/src/interface.rs
index 0462cfb..d3dbc2e 100644
--- a/tests/rust_tree/src/interface.rs
+++ b/tests/rust_tree/src/interface.rs
@@ -55,6 +55,15 @@ impl QStringIn {
     }
 }
 
+impl<'a> From<&'a str> for QString {
+    fn from(string: &'a str) -> QString {
+        QString {
+            len: string.len() as c_int,
+            data: string.as_ptr(),
+        }
+    }
+}
+
 impl<'a> From<&'a String> for QString {
     fn from(string: &'a String) -> QString {
         QString {
@@ -146,7 +155,7 @@ pub trait PersonsTrait {
     fn index(&self, item: Option<usize>, row: usize) -> usize;
     fn parent(&self, item: usize) -> Option<usize>;
     fn row(&self, item: usize) -> usize;
-    fn user_name(&self, item: usize) -> String;
+    fn user_name(&self, item: usize) -> &str;
     fn set_user_name(&mut self, item: usize, String) -> bool;
 }
 
@@ -264,7 +273,7 @@ pub unsafe extern "C" fn persons_data_user_name(
     set: fn(*mut c_void, QString),
 ) {
     let data = (&*ptr).user_name(item);
-    set(d, QString::from(&data));
+    set(d, (data).into());
 }
 
 #[no_mangle]