diff --git a/Gir_Gst.toml b/Gir_Gst.toml
index ec4d43a88..52b2c677f 100644
--- a/Gir_Gst.toml
+++ b/Gir_Gst.toml
@@ -37,7 +37,6 @@ generate = [
     "Gst.URIError",
     "Gst.StructureChangeType",
     "Gst.StreamStatusType",
-    "Gst.Device",
     "Gst.DeviceMonitor",
     "Gst.DeviceProvider",
     "Gst.DeviceProviderFactory",
@@ -52,6 +51,7 @@ generate = [
 manual = [
     "GLib.Error",
     "Gst.Message",
+    "Gst.Structure",
 ]
 
 [[object]]
@@ -160,6 +160,20 @@ name = "Gst.ElementFactory"
 status = "generate"
 trait = false
 
+[[object]]
+name = "Gst.Device"
+status = "generate"
+    [[object.function]]
+    name = "get_properties"
+    # Structure is not a GObject
+    ignore = true
+
+    [[object.property]]
+    name = "properties"
+    # Structure is not a GObject
+    ignore = true
+
+
 [[object]]
 name = "Gst.Object"
 status = "generate"
diff --git a/gstreamer/src/auto/device.rs b/gstreamer/src/auto/device.rs
index bdad07244..25f38a187 100644
--- a/gstreamer/src/auto/device.rs
+++ b/gstreamer/src/auto/device.rs
@@ -35,8 +35,6 @@ pub trait DeviceExt {
 
     fn get_display_name(&self) -> Option<String>;
 
-    //fn get_properties(&self) -> /*Ignored*/Option<Structure>;
-
     fn has_classes(&self, classes: &str) -> bool;
 
     fn has_classesv(&self, classes: &[&str]) -> bool;
@@ -49,8 +47,6 @@ pub trait DeviceExt {
 
     fn get_property_display_name(&self) -> Option<String>;
 
-    //fn get_property_properties(&self) -> /*Ignored*/Option<Structure>;
-
     fn connect_removed<F: Fn(&Self) + Send + Sync + 'static>(&self, f: F) -> u64;
 }
 
@@ -79,10 +75,6 @@ impl<O: IsA<Device> + IsA<glib::object::Object>> DeviceExt for O {
         }
     }
 
-    //fn get_properties(&self) -> /*Ignored*/Option<Structure> {
-    //    unsafe { TODO: call ffi::gst_device_get_properties() }
-    //}
-
     fn has_classes(&self, classes: &str) -> bool {
         unsafe {
             from_glib(ffi::gst_device_has_classes(self.to_glib_none().0, classes.to_glib_none().0))
@@ -125,14 +117,6 @@ impl<O: IsA<Device> + IsA<glib::object::Object>> DeviceExt for O {
         value.get()
     }
 
-    //fn get_property_properties(&self) -> /*Ignored*/Option<Structure> {
-    //    let mut value = Value::from(None::<&/*Ignored*/Structure>);
-    //    unsafe {
-    //        gobject_ffi::g_object_get_property(self.to_glib_none().0, "properties".to_glib_none().0, value.to_glib_none_mut().0);
-    //    }
-    //    value.get()
-    //}
-
     fn connect_removed<F: Fn(&Self) + Send + Sync + 'static>(&self, f: F) -> u64 {
         unsafe {
             let f: Box_<Box_<Fn(&Self) + Send + Sync + 'static>> = Box_::new(Box_::new(f));
diff --git a/gstreamer/src/auto/element.rs b/gstreamer/src/auto/element.rs
index 7c860b1c5..4fcbb7d91 100644
--- a/gstreamer/src/auto/element.rs
+++ b/gstreamer/src/auto/element.rs
@@ -146,7 +146,7 @@ pub trait ElementExt {
     //fn message_full<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32);
 
     //#[cfg(feature = "v1_10")]
-    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: /*Ignored*/&mut Structure);
+    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: &mut Structure);
 
     fn no_more_pads(&self);
 
@@ -394,7 +394,7 @@ impl<O: IsA<Element> + IsA<glib::object::Object>> ElementExt for O {
     //}
 
     //#[cfg(feature = "v1_10")]
-    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: /*Ignored*/&mut Structure) {
+    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: &mut Structure) {
     //    unsafe { TODO: call ffi::gst_element_message_full_with_details() }
     //}
 
diff --git a/gstreamer/src/auto/functions.rs b/gstreamer/src/auto/functions.rs
index e882b3e59..4f386a31b 100644
--- a/gstreamer/src/auto/functions.rs
+++ b/gstreamer/src/auto/functions.rs
@@ -224,7 +224,7 @@ pub fn is_initialized() -> bool {
     }
 }
 
-//pub fn make_element_message_details(name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) -> /*Ignored*/Option<Structure> {
+//pub fn make_element_message_details(name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) -> Option<Structure> {
 //    unsafe { TODO: call ffi::gst_make_element_message_details() }
 //}
 
@@ -641,7 +641,7 @@ pub fn util_uint64_scale_round(val: u64, num: u64, denom: u64) -> u64 {
 //    unsafe { TODO: call ffi::gst_value_get_int_range_step() }
 //}
 
-//pub fn value_get_structure(value: /*Ignored*/&glib::Value) -> /*Ignored*/Option<Structure> {
+//pub fn value_get_structure(value: /*Ignored*/&glib::Value) -> Option<Structure> {
 //    unsafe { TODO: call ffi::gst_value_get_structure() }
 //}
 
@@ -717,7 +717,7 @@ pub fn util_uint64_scale_round(val: u64, num: u64, denom: u64) -> u64 {
 //    unsafe { TODO: call ffi::gst_value_set_int_range_step() }
 //}
 
-//pub fn value_set_structure(value: /*Ignored*/&mut glib::Value, structure: /*Ignored*/&Structure) {
+//pub fn value_set_structure(value: /*Ignored*/&mut glib::Value, structure: &Structure) {
 //    unsafe { TODO: call ffi::gst_value_set_structure() }
 //}
 
diff --git a/gstreamer/src/auto/plugin.rs b/gstreamer/src/auto/plugin.rs
index 59e8cfaa9..5d6594f81 100644
--- a/gstreamer/src/auto/plugin.rs
+++ b/gstreamer/src/auto/plugin.rs
@@ -3,6 +3,7 @@
 
 use Error;
 use Object;
+use Structure;
 use ffi;
 use glib::translate::*;
 use std::ptr;
@@ -24,9 +25,11 @@ impl Plugin {
     //    unsafe { TODO: call ffi::gst_plugin_add_dependency_simple() }
     //}
 
-    //pub fn get_cache_data(&self) -> /*Ignored*/Option<Structure> {
-    //    unsafe { TODO: call ffi::gst_plugin_get_cache_data() }
-    //}
+    pub fn get_cache_data(&self) -> Option<Structure> {
+        unsafe {
+            from_glib_none(ffi::gst_plugin_get_cache_data(self.to_glib_none().0))
+        }
+    }
 
     pub fn get_description(&self) -> Option<String> {
         unsafe {
@@ -88,9 +91,11 @@ impl Plugin {
         }
     }
 
-    //pub fn set_cache_data(&self, cache_data: /*Ignored*/&mut Structure) {
-    //    unsafe { TODO: call ffi::gst_plugin_set_cache_data() }
-    //}
+    pub fn set_cache_data(&self, cache_data: &mut Structure) {
+        unsafe {
+            ffi::gst_plugin_set_cache_data(self.to_glib_none().0, cache_data.to_glib_full());
+        }
+    }
 
     pub fn list_free(list: &[Plugin]) {
         unsafe {
diff --git a/gstreamer/src/lib.rs b/gstreamer/src/lib.rs
index 82c2c2850..9c70776cf 100644
--- a/gstreamer/src/lib.rs
+++ b/gstreamer/src/lib.rs
@@ -47,6 +47,8 @@ pub use miniobject::GstRc;
 pub mod message;
 pub use message::Message;
 pub use message::MessageView;
+pub mod structure;
+pub use structure::Structure;
 
 mod element;
 mod bin;
diff --git a/gstreamer/src/message.rs b/gstreamer/src/message.rs
index 7c0854468..47612495f 100644
--- a/gstreamer/src/message.rs
+++ b/gstreamer/src/message.rs
@@ -723,9 +723,10 @@ macro_rules! message_builder_generic_impl {
             }
         }
 
-        pub fn build(self) -> Message {
+        pub fn build(mut self) -> Message {
             unsafe {
-                let msg = $new_fn(&self, self.src.to_glib_none().0);
+                let src = self.src.to_glib_none().0;
+                let msg = $new_fn(&mut self, src);
                 if let Some(seqnum) = self.seqnum {
                     ffi::gst_message_set_seqnum(msg, seqnum);
                 }
@@ -776,7 +777,7 @@ impl<'a> ErrorBuilder<'a> {
 
     // TODO details
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_error(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_error(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
 }
 
 pub struct WarningBuilder<'a> {
@@ -802,7 +803,7 @@ impl<'a> WarningBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_warning(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_warning(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
 }
 
 pub struct InfoBuilder<'a> {
@@ -830,7 +831,7 @@ impl<'a> InfoBuilder<'a> {
 
     // TODO details
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_warning(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_warning(src, mut_override(s.error.to_glib_none().0), s.debug.to_glib_none().0));
 }
 
 pub struct TagBuilder<'a> {
@@ -874,7 +875,7 @@ impl<'a> BufferingBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_buffering(src, s.percent);
 
         if let Some((mode, avg_in, avg_out, buffering_left)) = s.stats {
@@ -903,7 +904,7 @@ impl<'a> StateChangedBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_state_changed(src, s.old.to_glib(), s.new.to_glib(), s.pending.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_state_changed(src, s.old.to_glib(), s.new.to_glib(), s.pending.to_glib()));
 }
 
 pub struct StateDirtyBuilder<'a> {
@@ -947,7 +948,7 @@ impl<'a> StepDoneBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_step_done(src, s.format.to_glib(), s.amount, s.rate, s.flush.to_glib(), s.intermediate.to_glib(), s.duration, s.eos.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_step_done(src, s.format.to_glib(), s.amount, s.rate, s.flush.to_glib(), s.intermediate.to_glib(), s.duration, s.eos.to_glib()));
 }
 
 pub struct ClockProvideBuilder<'a> {
@@ -966,7 +967,7 @@ impl<'a> ClockProvideBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_clock_provide(src, s.clock.to_glib_none().0, s.ready.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_clock_provide(src, s.clock.to_glib_none().0, s.ready.to_glib()));
 }
 
 pub struct ClockLostBuilder<'a> {
@@ -983,7 +984,7 @@ impl<'a> ClockLostBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_clock_lost(src, s.clock.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_clock_lost(src, s.clock.to_glib_none().0));
 }
 
 pub struct NewClockBuilder<'a> {
@@ -1000,7 +1001,7 @@ impl<'a> NewClockBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_new_clock(src, s.clock.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_new_clock(src, s.clock.to_glib_none().0));
 }
 
 pub struct StructureChangeBuilder<'a> {
@@ -1021,7 +1022,7 @@ impl<'a> StructureChangeBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_structure_change(src, s.type_.to_glib(), s.owner.to_glib_none().0, s.busy.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_structure_change(src, s.type_.to_glib(), s.owner.to_glib_none().0, s.busy.to_glib()));
 }
 
 pub struct StreamStatusBuilder<'a> {
@@ -1049,7 +1050,7 @@ impl<'a> StreamStatusBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_stream_status(src, s.type_.to_glib(), s.owner.to_glib_none().0);
         if let Some(status_object) = s.status_object {
             ffi::gst_message_set_stream_status_object(msg, status_object.to_glib_none().0);
@@ -1058,40 +1059,38 @@ impl<'a> StreamStatusBuilder<'a> {
     });
 }
 
-// TODO Structure
 pub struct ApplicationBuilder<'a> {
     src: Option<&'a Object>,
     seqnum: Option<u32>,
-    structure: (),
+    structure: Option<::Structure>,
 }
 impl<'a> ApplicationBuilder<'a> {
-    pub fn new(structure: () /* &'a Structure */) -> Self {
+    pub fn new(structure: ::Structure) -> Self {
         Self {
             src: None,
             seqnum: None,
-            structure: structure,
+            structure: Some(structure),
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_application(src, ptr::null_mut() /*s.structure.to_glib_full()*/));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_application(src, s.structure.take().unwrap().into_ptr()));
 }
 
-// TODO Structure
 pub struct ElementBuilder<'a> {
     src: Option<&'a Object>,
     seqnum: Option<u32>,
-    structure: (),
+    structure: Option<::Structure>,
 }
 impl<'a> ElementBuilder<'a> {
-    pub fn new(structure: () /* &'a Structure */) -> Self {
+    pub fn new(structure: ::Structure) -> Self {
         Self {
             src: None,
             seqnum: None,
-            structure: structure,
+            structure: Some(structure),
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_element(src, ptr::null_mut() /*s.structure.to_glib_full()*/));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_element(src, s.structure.take().unwrap().into_ptr()));
 }
 
 pub struct SegmentStartBuilder<'a> {
@@ -1110,7 +1109,7 @@ impl<'a> SegmentStartBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_segment_start(src, s.format.to_glib(), s.position));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_segment_start(src, s.format.to_glib(), s.position));
 }
 
 pub struct SegmentDoneBuilder<'a> {
@@ -1129,7 +1128,7 @@ impl<'a> SegmentDoneBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_segment_done(src, s.format.to_glib(), s.position));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_segment_done(src, s.format.to_glib(), s.position));
 }
 
 pub struct DurationChangedBuilder<'a> {
@@ -1191,7 +1190,7 @@ impl<'a> AsyncDoneBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_async_done(src, s.running_time));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_async_done(src, s.running_time));
 }
 
 pub struct RequestStateBuilder<'a> {
@@ -1208,7 +1207,7 @@ impl<'a> RequestStateBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_request_state(src, s.state.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_request_state(src, s.state.to_glib()));
 }
 
 pub struct StepStartBuilder<'a> {
@@ -1235,7 +1234,7 @@ impl<'a> StepStartBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_step_start(src, s.active.to_glib(), s.format.to_glib(), s.amount, s.rate, s.flush.to_glib(), s.intermediate.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_step_start(src, s.active.to_glib(), s.format.to_glib(), s.amount, s.rate, s.flush.to_glib(), s.intermediate.to_glib()));
 }
 
 pub struct QosBuilder<'a> {
@@ -1278,7 +1277,7 @@ impl<'a> QosBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_qos(src, s.live.to_glib(), s.running_time, s.stream_time, s.timestamp, s.duration);
         if let Some((jitter, proportion, quality)) = s.values {
             ffi::gst_message_set_qos_values(msg, jitter, proportion, quality);
@@ -1322,7 +1321,7 @@ impl<'a> ProgressBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_progress(src, s.type_.to_glib(), s.code.to_glib_none().0, s.text.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_progress(src, s.type_.to_glib(), s.code.to_glib_none().0, s.text.to_glib_none().0));
 }
 
 // TODO Toc
@@ -1342,7 +1341,7 @@ impl<'a> TocBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_toc(src, ptr::null_mut() /*s.structure.to_glib_full()*/, s.updated.to_glib()));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_toc(src, ptr::null_mut() /*s.structure.to_glib_full()*/, s.updated.to_glib()));
 }
 
 pub struct ResetTimeBuilder<'a> {
@@ -1359,7 +1358,7 @@ impl<'a> ResetTimeBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_reset_time(src, s.running_time));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_reset_time(src, s.running_time));
 }
 
 pub struct StreamStartBuilder<'a> {
@@ -1383,7 +1382,7 @@ impl<'a> StreamStartBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_stream_start(src);
         if let Some(group_id) = s.group_id {
             ffi::gst_message_set_group_id(msg, group_id);
@@ -1406,7 +1405,7 @@ impl<'a> NeedContextBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_need_context(src, s.context_type.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_need_context(src, s.context_type.to_glib_none().0));
 }
 
 // TODO Context
@@ -1424,7 +1423,7 @@ impl<'a> HaveContextBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_have_context(src, ptr::null_mut() /*s.context.to_glib_full().0*/));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_have_context(src, ptr::null_mut() /*s.context.to_glib_full().0*/));
 }
 
 pub struct DeviceAddedBuilder<'a> {
@@ -1441,7 +1440,7 @@ impl<'a> DeviceAddedBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_device_added(src, s.device.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_device_added(src, s.device.to_glib_none().0));
 }
 
 pub struct DeviceRemovedBuilder<'a> {
@@ -1458,7 +1457,7 @@ impl<'a> DeviceRemovedBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_device_removed(src, s.device.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_device_removed(src, s.device.to_glib_none().0));
 }
 
 pub struct PropertyNotifyBuilder<'a> {
@@ -1478,7 +1477,7 @@ impl<'a> PropertyNotifyBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_property_notify(src, s.property_name.to_glib_none().0, mut_override(s.value.to_glib_none().0)));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_property_notify(src, s.property_name.to_glib_none().0, mut_override(s.value.to_glib_none().0)));
 }
 
 pub struct StreamCollectionBuilder<'a> {
@@ -1497,7 +1496,7 @@ impl<'a> StreamCollectionBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| ffi::gst_message_new_stream_collection(src, s.collection.to_glib_none().0));
+    message_builder_generic_impl!(|s: &mut Self, src| ffi::gst_message_new_stream_collection(src, s.collection.to_glib_none().0));
 }
 
 pub struct StreamsSelectedBuilder<'a> {
@@ -1526,7 +1525,7 @@ impl<'a> StreamsSelectedBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_streams_selected(src, s.collection.to_glib_none().0);
         if let Some(streams) = s.streams {
             for stream in streams {
@@ -1566,7 +1565,7 @@ impl<'a> RedirectBuilder<'a> {
         }
     }
 
-    message_builder_generic_impl!(|s: &Self, src| {
+    message_builder_generic_impl!(|s: &mut Self, src| {
         let msg = ffi::gst_message_new_redirect(src, s.location.to_glib_none().0, ptr::null_mut(), ptr::null_mut());
         if let Some(entries) = s.entries {
             for &(location, tag_list, entry_struct) in entries {
diff --git a/gstreamer/src/structure.rs b/gstreamer/src/structure.rs
new file mode 100644
index 000000000..13a121e0f
--- /dev/null
+++ b/gstreamer/src/structure.rs
@@ -0,0 +1,509 @@
+// Copyright (C) 2016-2017 Sebastian Dröge <sebastian@centricular.com>
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::fmt;
+use std::ptr;
+use std::mem;
+use std::ffi::{CStr, CString};
+use std::ops::{Deref, DerefMut};
+use std::borrow::{Borrow, ToOwned, BorrowMut};
+use std::marker::PhantomData;
+
+use glib;
+use glib::translate::{from_glib, from_glib_full, from_glib_none, Stash, StashMut, ToGlibPtr, ToGlibPtrMut, FromGlibPtrNone, FromGlibPtrBorrow, FromGlibPtrFull};
+use glib::value::{Value, ToValue, FromValueOptional};
+use ffi;
+use glib_ffi;
+
+pub struct Structure(*mut StructureRef, PhantomData<StructureRef>, bool);
+
+impl Structure {
+    pub fn new_empty(name: &str) -> Structure {
+        Structure(
+            unsafe { ffi::gst_structure_new_empty(name.to_glib_none().0) as *mut StructureRef },
+            PhantomData,
+            false,
+        )
+    }
+
+    pub fn new(name: &str, values: &[(&str, &Value)]) -> Structure {
+        let mut structure = Structure::new_empty(name);
+
+        for &(f, v) in values {
+            structure.set_value(f, v.clone());
+        }
+
+        structure
+    }
+
+    pub fn from_string(s: &str) -> Option<Structure> {
+        unsafe {
+            let structure = ffi::gst_structure_from_string(s.to_glib_none().0, ptr::null_mut());
+            if structure.is_null() {
+                None
+            } else {
+                Some(Structure(structure as *mut StructureRef, PhantomData, false))
+            }
+        }
+    }
+
+    pub unsafe fn into_ptr(self) -> *mut ffi::GstStructure {
+        let ptr = self.0 as *mut StructureRef as *mut ffi::GstStructure;
+        mem::forget(self);
+
+        ptr
+    }
+}
+
+impl Deref for Structure {
+    type Target = StructureRef;
+
+    fn deref(&self) -> &StructureRef {
+        unsafe { &*self.0 }
+    }
+}
+
+impl DerefMut for Structure {
+    fn deref_mut(&mut self) -> &mut StructureRef {
+        unsafe { &mut *self.0 }
+    }
+}
+
+impl AsRef<StructureRef> for Structure {
+    fn as_ref(&self) -> &StructureRef {
+        self.deref()
+    }
+}
+
+impl AsMut<StructureRef> for Structure {
+    fn as_mut(&mut self) -> &mut StructureRef {
+        self.deref_mut()
+    }
+}
+
+impl Clone for Structure {
+    fn clone(&self) -> Self {
+        Structure(
+            unsafe { ffi::gst_structure_copy(&(*self.0).0) as *mut StructureRef },
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl Drop for Structure {
+    fn drop(&mut self) {
+        if !self.2 {
+            unsafe { ffi::gst_structure_free(&mut (*self.0).0) }
+        }
+    }
+}
+
+impl fmt::Debug for Structure {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.to_string())
+    }
+}
+
+impl PartialEq for Structure {
+    fn eq(&self, other: &Structure) -> bool {
+        self.as_ref().eq(other)
+    }
+}
+
+impl PartialEq<StructureRef> for Structure {
+    fn eq(&self, other: &StructureRef) -> bool {
+        self.as_ref().eq(other)
+    }
+}
+
+impl Eq for Structure {}
+
+impl Borrow<StructureRef> for Structure {
+    fn borrow(&self) -> &StructureRef {
+        unsafe { &*self.0 }
+    }
+}
+
+impl BorrowMut<StructureRef> for Structure {
+    fn borrow_mut(&mut self) -> &mut StructureRef {
+        unsafe { &mut *self.0 }
+    }
+}
+
+impl ToOwned for StructureRef {
+    type Owned = Structure;
+
+    fn to_owned(&self) -> Structure {
+        Structure(
+            unsafe { ffi::gst_structure_copy(&self.0) as *mut StructureRef },
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl<'a> ToGlibPtr<'a, *const ffi::GstStructure> for Structure {
+    type Storage = &'a Self;
+
+    fn to_glib_none(&'a self) -> Stash<'a, *const ffi::GstStructure, Self> {
+        Stash(unsafe { &(*self.0).0 }, self)
+    }
+
+    fn to_glib_full(&self) -> *const ffi::GstStructure {
+        unsafe {
+            ffi::gst_structure_copy(&(*self.0).0)
+        }
+    }
+}
+
+impl<'a> ToGlibPtr<'a, *mut ffi::GstStructure> for Structure {
+    type Storage = &'a Self;
+
+    fn to_glib_none(&'a self) -> Stash<'a, *mut ffi::GstStructure, Self> {
+        Stash(unsafe { &mut (*self.0).0 }, self)
+    }
+
+    fn to_glib_full(&self) -> *mut ffi::GstStructure {
+        unsafe {
+            ffi::gst_structure_copy(&(*self.0).0)
+        }
+    }
+}
+
+impl<'a> ToGlibPtrMut<'a, *mut ffi::GstStructure> for Structure {
+    type Storage = &'a mut Self;
+
+    fn to_glib_none_mut(&'a mut self) -> StashMut<*mut ffi::GstStructure, Self> {
+        StashMut(unsafe { &mut (*self.0).0 }, self)
+    }
+}
+
+impl FromGlibPtrNone<*const ffi::GstStructure> for Structure {
+    unsafe fn from_glib_none(ptr: *const ffi::GstStructure) -> Self {
+        Structure(
+            ffi::gst_structure_copy(ptr) as *mut StructureRef,
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl FromGlibPtrNone<*mut ffi::GstStructure> for Structure {
+    unsafe fn from_glib_none(ptr: *mut ffi::GstStructure) -> Self {
+        Structure(
+            ffi::gst_structure_copy(ptr) as *mut StructureRef,
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl FromGlibPtrFull<*const ffi::GstStructure> for Structure {
+    unsafe fn from_glib_full(ptr: *const ffi::GstStructure) -> Self {
+        Structure(
+            ptr as *mut StructureRef,
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl FromGlibPtrFull<*mut ffi::GstStructure> for Structure {
+    unsafe fn from_glib_full(ptr: *mut ffi::GstStructure) -> Self {
+        Structure(
+            ptr as *mut StructureRef,
+            PhantomData,
+            false,
+        )
+    }
+}
+
+impl FromGlibPtrBorrow<*const ffi::GstStructure> for Structure {
+    unsafe fn from_glib_borrow(ptr: *const ffi::GstStructure) -> Self {
+        Structure(
+            ptr as *mut StructureRef,
+            PhantomData,
+            true,
+        )
+    }
+}
+
+impl FromGlibPtrBorrow<*mut ffi::GstStructure> for Structure {
+    unsafe fn from_glib_borrow(ptr: *mut ffi::GstStructure) -> Self {
+        Structure(
+            ptr as *mut StructureRef,
+            PhantomData,
+            true,
+        )
+    }
+}
+
+#[repr(C)]
+pub struct StructureRef(ffi::GstStructure);
+
+impl StructureRef {
+    pub unsafe fn from_glib_borrow<'a>(ptr: *const ffi::GstStructure) -> &'a StructureRef {
+        assert!(!ptr.is_null());
+
+        &*(ptr as *mut StructureRef)
+    }
+
+    pub unsafe fn from_glib_borrow_mut<'a>(ptr: *mut ffi::GstStructure) -> &'a mut StructureRef {
+        assert!(!ptr.is_null());
+
+        &mut *(ptr as *mut StructureRef)
+    }
+
+    pub fn to_string(&self) -> String {
+        unsafe {
+            from_glib_full(ffi::gst_structure_to_string(&self.0))
+        }
+    }
+
+    pub fn get<'a, T: FromValueOptional<'a>>(&'a self, name: &str) -> Option<T> {
+        self.get_value(name).and_then(|v| v.get())
+    }
+
+    pub fn get_value<'a>(&'a self, name: &str) -> Option<&Value> {
+        unsafe {
+            let name_cstr = CString::new(name).unwrap();
+
+            let value = ffi::gst_structure_get_value(&self.0, name_cstr.as_ptr());
+
+            if value.is_null() {
+                return None;
+            }
+
+            Some(&*(value as *const Value))
+        }
+    }
+
+    pub fn set<T: ToValue>(&mut self, name: &str, value: T) {
+        let value = value.to_value();
+        self.set_value(name, value);
+    }
+
+    pub fn set_value(&mut self, name: &str, mut value: Value) {
+        unsafe {
+            let name_cstr = CString::new(name).unwrap();
+            ffi::gst_structure_take_value(&mut self.0, name_cstr.as_ptr(), value.to_glib_none_mut().0);
+            mem::forget(value);
+        }
+    }
+
+    pub fn get_name(&self) -> &str {
+        unsafe {
+            CStr::from_ptr(ffi::gst_structure_get_name(&self.0)).to_str().unwrap()
+        }
+    }
+
+    pub fn has_field(&self, field: &str) -> bool {
+        unsafe {
+            from_glib(ffi::gst_structure_has_field(&self.0, field.to_glib_none().0))
+        }
+    }
+
+    pub fn remove_field(&mut self, field: &str) {
+        unsafe {
+            ffi::gst_structure_remove_field(&mut self.0, field.to_glib_none().0);
+        }
+    }
+
+    pub fn remove_all_fields(&mut self) {
+        unsafe {
+            ffi::gst_structure_remove_all_fields(&mut self.0);
+        }
+    }
+
+    pub fn fields(&self) -> FieldIterator {
+        FieldIterator::new(self)
+    }
+
+    pub fn iter(&self) -> Iter {
+        Iter::new(self)
+    }
+
+    fn get_nth_field_name(&self, idx: u32) -> Option<&str> {
+        unsafe {
+            let field_name = ffi::gst_structure_nth_field_name(&self.0, idx);
+            if field_name.is_null() {
+                return None;
+            }
+
+            Some(CStr::from_ptr(field_name).to_str().unwrap())
+        }
+    }
+
+    fn n_fields(&self) -> u32 {
+        unsafe { ffi::gst_structure_n_fields(&self.0) as u32 }
+    }
+
+    // TODO: Various operations
+}
+
+impl fmt::Debug for StructureRef {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.to_string())
+    }
+}
+
+impl PartialEq for StructureRef {
+    fn eq(&self, other: &StructureRef) -> bool {
+        unsafe { from_glib(ffi::gst_structure_is_equal(&self.0, &other.0)) }
+    }
+}
+
+impl Eq for StructureRef {}
+
+pub struct FieldIterator<'a> {
+    structure: &'a StructureRef,
+    idx: u32,
+    n_fields: u32,
+}
+
+impl<'a> FieldIterator<'a> {
+    pub fn new(structure: &'a StructureRef) -> FieldIterator<'a> {
+        let n_fields = structure.n_fields();
+
+        FieldIterator {
+            structure: structure,
+            idx: 0,
+            n_fields: n_fields,
+        }
+    }
+}
+
+impl<'a> Iterator for FieldIterator<'a> {
+    type Item = &'a str;
+
+    fn next(&mut self) -> Option<&'a str> {
+        if self.idx >= self.n_fields {
+            return None;
+        }
+
+        if let Some(field_name) = self.structure.get_nth_field_name(self.idx) {
+            self.idx += 1;
+            Some(field_name)
+        } else {
+            None
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if self.idx == self.n_fields {
+            return (0, Some(0));
+        }
+
+        let remaining = (self.n_fields - self.idx) as usize;
+
+        (remaining, Some(remaining))
+    }
+}
+
+impl<'a> DoubleEndedIterator for FieldIterator<'a> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if self.idx == self.n_fields {
+            return None;
+        }
+
+        self.n_fields -= 1;
+        if let Some(field_name) = self.structure.get_nth_field_name(self.n_fields) {
+            Some(field_name)
+        } else {
+            None
+        }
+    }
+}
+
+impl<'a> ExactSizeIterator for FieldIterator<'a> {}
+
+pub struct Iter<'a> {
+    iter: FieldIterator<'a>,
+}
+
+impl<'a> Iter<'a> {
+    pub fn new(structure: &'a StructureRef) -> Iter<'a> {
+        Iter { iter: FieldIterator::new(structure) }
+    }
+}
+
+impl<'a> Iterator for Iter<'a> {
+    type Item = (&'a str, &'a Value);
+
+    fn next(&mut self) -> Option<(&'a str, &'a Value)> {
+        if let Some(f) = self.iter.next() {
+            let v = self.iter.structure.get_value(f);
+            Some((f, v.unwrap()))
+        } else {
+            None
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+}
+
+impl<'a> DoubleEndedIterator for Iter<'a> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if let Some(f) = self.iter.next_back() {
+            let v = self.iter.structure.get_value(f);
+            Some((f, v.unwrap()))
+        } else {
+            None
+        }
+    }
+}
+
+impl<'a> ExactSizeIterator for Iter<'a> {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn new_set_get() {
+        ::init().unwrap();
+
+        let mut s = Structure::new_empty("test");
+        assert_eq!(s.get_name(), "test");
+
+        s.set("f1", "abc");
+        s.set("f2", String::from("bcd"));
+        s.set("f3", 123i32);
+
+        assert_eq!(s.get::<&str>("f1").unwrap(), "abc");
+        assert_eq!(s.get::<&str>("f2").unwrap(), "bcd");
+        assert_eq!(s.get::<i32>("f3").unwrap(), 123i32);
+
+        assert_eq!(s.fields().collect::<Vec<_>>(), vec!["f1", "f2", "f3"]);
+        /*
+        assert_eq!(
+            s.iter()
+                .map(|(f, v)| (f, v.clone()))
+                .collect::<Vec<_>>(),
+            vec![
+                ("f1", "abc".into()),
+                ("f2","bcd".into()),
+                ("f3", 123i32.into()),
+            ]
+        );
+
+        let s2 = Structure::new(
+            "test",
+            &[
+                ("f1", "abc".into()),
+                ("f2", "bcd".into()),
+                ("f3", 123i32.into()),
+            ],
+        );
+        assert_eq!(s, s2);
+*/
+    }
+}