diff --git a/level_zero/src/ze.rs b/level_zero/src/ze.rs
index 88adfe6..f4cd0ae 100644
--- a/level_zero/src/ze.rs
+++ b/level_zero/src/ze.rs
@@ -737,129 +737,122 @@ impl<'a> CommandList<'a> {
         Ok(unsafe { Self::from_ffi(result) })
     }
 
-    pub fn append_memory_copy<'event, T: 'a, Dst: Into<Slice<'a, T>>, Src: Into<Slice<'a, T>>>(
-        &'a self,
+    pub unsafe fn append_memory_copy<
+        'dep,
+        T: 'a + 'dep + Copy + Sized,
+        Dst: Into<Slice<'dep, T>>,
+        Src: Into<Slice<'dep, T>>,
+    >(
+        &self,
         dst: Dst,
         src: Src,
-        signal: Option<&Event<'event>>,
-        wait: &[Event<'event>],
-    ) -> Result<()>
-    where
-        'event: 'a,
-    {
+        signal: Option<&Event<'dep>>,
+        wait: &[&'dep Event<'dep>],
+    ) -> Result<()> {
         let dst = dst.into();
         let src = src.into();
         let elements = std::cmp::min(dst.len(), src.len());
         let length = elements * mem::size_of::<T>();
-        unsafe {
-            self.append_memory_copy_unsafe(dst.as_mut_ptr(), src.as_ptr(), length, signal, wait)
-        }
+        self.append_memory_copy_raw(dst.as_mut_ptr(), src.as_ptr(), length, signal, wait)
     }
 
-    pub unsafe fn append_memory_copy_unsafe(
+    pub unsafe fn append_memory_copy_raw(
         &self,
         dst: *mut c_void,
         src: *const c_void,
         length: usize,
         signal: Option<&Event>,
-        wait: &[Event],
+        wait: &[&Event],
     ) -> Result<()> {
-        let signal_event = signal.map(|e| e.as_ffi()).unwrap_or(ptr::null_mut());
-        let (wait_len, wait_ptr) = Event::raw_slice(wait);
-        check!(sys::zeCommandListAppendMemoryCopy(
-            self.as_ffi(),
-            dst,
-            src,
-            length,
-            signal_event,
-            wait_len,
-            wait_ptr
-        ));
-        Ok(())
+        let signal_event = signal.map_or(ptr::null_mut(), |e| e.as_ffi());
+        Event::with_raw_slice(wait, |wait_len, wait_ptr| {
+            check!(sys::zeCommandListAppendMemoryCopy(
+                self.as_ffi(),
+                dst,
+                src,
+                length,
+                signal_event,
+                wait_len,
+                wait_ptr
+            ));
+            Ok(())
+        })
     }
 
-    pub fn append_memory_fill<'event, T: 'a, Dst: Into<Slice<'a, T>>>(
+    pub unsafe fn append_memory_fill<'dep, T: Copy + Sized + 'dep, Dst: Into<Slice<'dep, T>>>(
         &'a self,
         dst: Dst,
-        pattern: u8,
-        signal: Option<&Event<'event>>,
-        wait: &[Event<'event>],
-    ) -> Result<()>
-    where
-        'event: 'a,
-    {
+        pattern: &T,
+        signal: Option<&Event<'dep>>,
+        wait: &[&'dep Event<'dep>],
+    ) -> Result<()> {
         let dst = dst.into();
-        let raw_pattern = &pattern as *const u8 as *const _;
-        let signal_event = signal
-            .map(|e| unsafe { e.as_ffi() })
-            .unwrap_or(ptr::null_mut());
-        let (wait_len, wait_ptr) = unsafe { Event::raw_slice(wait) };
-        let byte_len = dst.len() * mem::size_of::<T>();
-        check!(sys::zeCommandListAppendMemoryFill(
-            self.as_ffi(),
-            dst.as_mut_ptr(),
-            raw_pattern,
-            mem::size_of::<u8>(),
-            byte_len,
-            signal_event,
-            wait_len,
-            wait_ptr
-        ));
-        Ok(())
+        let raw_pattern = pattern as *const _ as *const _;
+        let signal_event = signal.map_or(ptr::null_mut(), |e| e.as_ffi());
+        Event::with_raw_slice(wait, |wait_len, wait_ptr| {
+            check!(sys::zeCommandListAppendMemoryFill(
+                self.as_ffi(),
+                dst.as_mut_ptr(),
+                raw_pattern,
+                mem::size_of::<T>(),
+                dst.len() * mem::size_of::<T>(),
+                signal_event,
+                wait_len,
+                wait_ptr
+            ));
+            Ok(())
+        })
     }
 
-    pub unsafe fn append_memory_fill_unsafe<T: Copy + Sized>(
+    pub unsafe fn append_memory_fill_raw(
         &self,
         dst: *mut c_void,
-        pattern: &T,
-        byte_size: usize,
+        pattern: *mut c_void,
+        pattern_size: usize,
+        size: usize,
         signal: Option<&Event>,
-        wait: &[Event],
+        wait: &[&Event],
     ) -> Result<()> {
-        let signal_event = signal.map(|e| e.as_ffi()).unwrap_or(ptr::null_mut());
-        let (wait_len, wait_ptr) = Event::raw_slice(wait);
-        check!(sys::zeCommandListAppendMemoryFill(
-            self.as_ffi(),
-            dst,
-            pattern as *const T as *const _,
-            mem::size_of::<T>(),
-            byte_size,
-            signal_event,
-            wait_len,
-            wait_ptr
-        ));
-        Ok(())
+        let signal_event = signal.map_or(ptr::null_mut(), |e| e.as_ffi());
+        Event::with_raw_slice(wait, |wait_len, wait_ptr| {
+            check!(sys::zeCommandListAppendMemoryFill(
+                self.as_ffi(),
+                dst,
+                pattern,
+                pattern_size,
+                size,
+                signal_event,
+                wait_len,
+                wait_ptr
+            ));
+            Ok(())
+        })
     }
 
-    pub fn append_launch_kernel<'event, 'kernel>(
-        &'a self,
-        kernel: &'kernel Kernel,
+    pub unsafe fn append_launch_kernel(
+        &self,
+        kernel: &Kernel,
         group_count: &[u32; 3],
-        signal: Option<&Event<'event>>,
-        wait: &[Event<'event>],
-    ) -> Result<()>
-    where
-        'event: 'a,
-        'kernel: 'a,
-    {
+        signal: Option<&Event>,
+        wait: &[&Event],
+    ) -> Result<()> {
         let gr_count = sys::ze_group_count_t {
             groupCountX: group_count[0],
             groupCountY: group_count[1],
             groupCountZ: group_count[2],
         };
-        let signal_event = signal
-            .map(|e| unsafe { e.as_ffi() })
-            .unwrap_or(ptr::null_mut());
-        let (wait_len, wait_ptr) = unsafe { Event::raw_slice(wait) };
-        check!(sys::zeCommandListAppendLaunchKernel(
-            self.as_ffi(),
-            kernel.as_ffi(),
-            &gr_count,
-            signal_event,
-            wait_len,
-            wait_ptr,
-        ));
-        Ok(())
+        let signal_event = signal.map_or(ptr::null_mut(), |e| e.as_ffi());
+        Event::with_raw_slice(wait, |wait_len, wait_ptr| {
+            check!(sys::zeCommandListAppendLaunchKernel(
+                self.as_ffi(),
+                kernel.as_ffi(),
+                &gr_count,
+                signal_event,
+                wait_len,
+                wait_ptr,
+            ));
+            Ok(())
+        })
     }
 
     pub fn close(&self) -> Result<()> {
@@ -875,17 +868,86 @@ impl<'a> Drop for CommandList<'a> {
     }
 }
 
+pub struct CommandListBuilder<'a>(CommandList<'a>);
+
+unsafe impl<'a> Send for CommandListBuilder<'a> {}
+
+impl<'a> CommandListBuilder<'a> {
+    pub fn new(ctx: &'a Context, dev: Device) -> Result<Self> {
+        Ok(CommandListBuilder(CommandList::new(ctx, dev)?))
+    }
+
+    pub fn append_memory_copy<
+        'dep,
+        'result,
+        T: 'dep + Copy + Sized,
+        Dst: Into<Slice<'dep, T>>,
+        Src: Into<Slice<'dep, T>>,
+    >(
+        self,
+        dst: Dst,
+        src: Src,
+        signal: Option<&'dep Event<'dep>>,
+        wait: &[&'dep Event<'dep>],
+    ) -> Result<CommandListBuilder<'result>>
+    where
+        'a: 'result,
+        'dep: 'result,
+    {
+        unsafe { self.0.append_memory_copy(dst, src, signal, wait) }?;
+        Ok(self)
+    }
+
+    pub fn append_memory_fill<'dep, 'result, T: 'dep + Copy + Sized, Dst: Into<Slice<'dep, T>>>(
+        self,
+        dst: Dst,
+        pattern: &T,
+        signal: Option<&Event<'dep>>,
+        wait: &[&'dep Event<'dep>],
+    ) -> Result<CommandListBuilder<'result>>
+    where
+        'a: 'result,
+        'dep: 'result,
+    {
+        unsafe { self.0.append_memory_fill(dst, pattern, signal, wait) }?;
+        Ok(self)
+    }
+
+    pub fn append_launch_kernel<'dep, 'result>(
+        self,
+        kernel: &'dep Kernel,
+        group_count: &[u32; 3],
+        signal: Option<&Event<'dep>>,
+        wait: &[&'dep Event<'dep>],
+    ) -> Result<CommandListBuilder<'result>>
+    where
+        'a: 'result,
+        'dep: 'result,
+    {
+        unsafe {
+            self.0
+                .append_launch_kernel(kernel, group_count, signal, wait)
+        }?;
+        Ok(self)
+    }
+
+    pub fn execute(self, q: &'a CommandQueue<'a>) -> Result<FenceGuard<'a>> {
+        self.0.close()?;
+        q.execute_and_synchronize(self.0)
+    }
+}
+
 #[derive(Copy, Clone)]
-pub struct Slice<'a, T> {
+pub struct Slice<'a, T: Copy + Sized> {
     ptr: *mut c_void,
     len: usize,
     marker: PhantomData<&'a T>,
 }
 
-unsafe impl<'a, T> Send for Slice<'a, T> {}
-unsafe impl<'a, T> Sync for Slice<'a, T> {}
+unsafe impl<'a, T: Copy + Sized> Send for Slice<'a, T> {}
+unsafe impl<'a, T: Copy + Sized> Sync for Slice<'a, T> {}
 
-impl<'a, T> Slice<'a, T> {
+impl<'a, T: Copy + Sized> Slice<'a, T> {
     pub unsafe fn new(ptr: *mut c_void, len: usize) -> Self {
         Self {
             ptr,
@@ -907,7 +969,7 @@ impl<'a, T> Slice<'a, T> {
     }
 }
 
-impl<'a, T> From<&'a [T]> for Slice<'a, T> {
+impl<'a, T: Copy + Sized> From<&'a [T]> for Slice<'a, T> {
     fn from(s: &'a [T]) -> Self {
         Slice {
             ptr: s.as_ptr() as *mut _,
@@ -917,7 +979,7 @@ impl<'a, T> From<&'a [T]> for Slice<'a, T> {
     }
 }
 
-impl<'a, T: Copy> From<&'a DeviceBuffer<'a, T>> for Slice<'a, T> {
+impl<'a, T: Copy + Sized> From<&'a DeviceBuffer<'a, T>> for Slice<'a, T> {
     fn from(b: &'a DeviceBuffer<'a, T>) -> Self {
         Slice {
             ptr: b.ptr,
@@ -996,13 +1058,21 @@ impl<'a> Event<'a> {
         Ok(unsafe { Self::from_ffi(result) })
     }
 
-    unsafe fn raw_slice(e: &[Event]) -> (u32, *mut sys::ze_event_handle_t) {
-        let ptr = if e.len() == 0 {
-            ptr::null()
-        } else {
-            e.as_ptr()
+    unsafe fn with_raw_slice<'x, T>(
+        events: &[&Event<'x>],
+        f: impl FnOnce(u32, *mut sys::ze_event_handle_t) -> T,
+    ) -> T {
+        let (ptr, ev_vec) = match events {
+            [] => (ptr::null_mut(), None),
+            [e] => (&e.0 as *const _ as *mut _, None),
+            _ => {
+                let mut ev_vec = events.iter().map(|e| e.as_ffi()).collect::<Vec<_>>();
+                (ev_vec.as_mut_ptr(), Some(ev_vec))
+            }
         };
-        (e.len() as u32, ptr as *mut sys::ze_event_handle_t)
+        let result = f(events.len() as u32, ptr);
+        drop(ev_vec);
+        result
     }
 }
 
@@ -1042,7 +1112,7 @@ impl<'a> Kernel<'a> {
         Ok(())
     }
 
-    pub fn set_arg_buffer<T: 'a, Buff: Into<Slice<'a, T>>>(
+    pub fn set_arg_buffer<T: 'a + Copy + Sized, Buff: Into<Slice<'a, T>>>(
         &self,
         index: u32,
         buff: Buff,
diff --git a/ptx/src/test/spirv_run/mod.rs b/ptx/src/test/spirv_run/mod.rs
index 94114db..c9ed9b1 100644
--- a/ptx/src/test/spirv_run/mod.rs
+++ b/ptx/src/test/spirv_run/mod.rs
@@ -202,7 +202,7 @@ impl<T: Debug> error::Error for DisplayError<T> {}
 fn test_ptx_assert<
     'a,
     Input: From<u8> + Debug + Copy + PartialEq,
-    Output: From<u8> + Debug + Copy + PartialEq,
+    Output: From<u8> + Debug + Copy + PartialEq + Default,
 >(
     name: &str,
     ptx_text: &'a str,
@@ -220,7 +220,7 @@ fn test_ptx_assert<
     Ok(())
 }
 
-fn run_spirv<Input: From<u8> + Copy + Debug, Output: From<u8> + Copy + Debug>(
+fn run_spirv<Input: From<u8> + Copy + Debug, Output: From<u8> + Copy + Debug + Default>(
     name: &CStr,
     module: translate::Module,
     input: &[Input],
@@ -286,19 +286,19 @@ fn run_spirv<Input: From<u8> + Copy + Debug, Output: From<u8> + Copy + Debug>(
         let ev1 = ze::Event::new(&event_pool, 1)?;
         let ev2 = ze::Event::new(&event_pool, 2)?;
         {
-            let cmd_list = ze::CommandList::new(&ctx, dev)?;
-            let init_evs = [ev0, ev1];
-            cmd_list.append_memory_copy(&inp_b, input, Some(&init_evs[0]), &[])?;
-            cmd_list.append_memory_fill(&out_b, 0, Some(&init_evs[1]), &[])?;
+            let init_evs = [&ev0, &ev1];
             kernel.set_group_size(1, 1, 1)?;
             kernel.set_arg_buffer(0, &inp_b)?;
             kernel.set_arg_buffer(1, &out_b)?;
             if use_shared_mem {
                 unsafe { kernel.set_arg_raw(2, 128, ptr::null())? };
             }
-            cmd_list.append_launch_kernel(&kernel, &[1, 1, 1], Some(&ev2), &init_evs)?;
-            cmd_list.append_memory_copy(&*result, &out_b, None, &[ev2])?;
-            queue.execute_and_synchronize(cmd_list)?;
+            ze::CommandListBuilder::new(&ctx, dev)?
+                .append_memory_copy(&inp_b, input, Some(&init_evs[0]), &[])?
+                .append_memory_fill(&out_b, &Output::default(), Some(&init_evs[1]), &[])?
+                .append_launch_kernel(&kernel, &[1, 1, 1], Some(&ev2), &init_evs)?
+                .append_memory_copy(&*result, &out_b, None, &[&ev2])?
+                .execute(&queue)?;
         }
     }
     Ok(result)
diff --git a/zluda/src/impl/function.rs b/zluda/src/impl/function.rs
index e236160..bcb7bd6 100644
--- a/zluda/src/impl/function.rs
+++ b/zluda/src/impl/function.rs
@@ -145,12 +145,14 @@ pub fn launch_kernel(
             .set_group_size(block_dim_x, block_dim_y, block_dim_z)?;
         func.legacy_args.reset();
         let cmd_list = stream.command_list()?;
-        cmd_list.append_launch_kernel(
-            &mut func.base,
-            &[grid_dim_x, grid_dim_y, grid_dim_z],
-            None,
-            &mut [],
-        )?;
+        unsafe {
+            cmd_list.append_launch_kernel(
+                &mut func.base,
+                &[grid_dim_x, grid_dim_y, grid_dim_z],
+                None,
+                &mut [],
+            )?;
+        }
         stream.queue.execute_and_synchronize(cmd_list)?;
         Ok(())
     })?
diff --git a/zluda/src/impl/memory.rs b/zluda/src/impl/memory.rs
index 5db6472..2a6236f 100644
--- a/zluda/src/impl/memory.rs
+++ b/zluda/src/impl/memory.rs
@@ -13,7 +13,7 @@ pub fn alloc_v2(dptr: *mut *mut c_void, bytesize: usize) -> Result<(), CUresult>
 pub fn copy_v2(dst: *mut c_void, src: *const c_void, bytesize: usize) -> Result<(), CUresult> {
     GlobalState::lock_stream(stream::CU_STREAM_LEGACY, |stream| {
         let cmd_list = stream.command_list()?;
-        unsafe { cmd_list.append_memory_copy_unsafe(dst, src, bytesize, None, &mut [])? };
+        unsafe { cmd_list.append_memory_copy_raw(dst, src, bytesize, None, &mut [])? };
         stream.queue.execute_and_synchronize(cmd_list)?;
         Ok::<_, CUresult>(())
     })?
@@ -27,22 +27,36 @@ pub fn free_v2(ptr: *mut c_void) -> Result<(), CUresult> {
     .map_err(|_| CUresult::CUDA_ERROR_INVALID_VALUE)?
 }
 
-pub(crate) fn set_d32_v2(dst: *mut c_void, ui: u32, n: usize) -> Result<(), CUresult> {
+pub(crate) fn set_d32_v2(dst: *mut c_void, mut ui: u32, n: usize) -> Result<(), CUresult> {
     GlobalState::lock_stream(stream::CU_STREAM_LEGACY, |stream| {
         let cmd_list = stream.command_list()?;
         unsafe {
-            cmd_list.append_memory_fill_unsafe(dst, &ui, mem::size_of::<u32>() * n, None, &mut [])
+            cmd_list.append_memory_fill_raw(
+                dst,
+                &mut ui as *mut _ as *mut _,
+                mem::size_of::<u32>(),
+                mem::size_of::<u32>() * n,
+                None,
+                &mut [],
+            )
         }?;
         stream.queue.execute_and_synchronize(cmd_list)?;
         Ok::<_, CUresult>(())
     })?
 }
 
-pub(crate) fn set_d8_v2(dst: *mut c_void, uc: u8, n: usize) -> Result<(), CUresult> {
+pub(crate) fn set_d8_v2(dst: *mut c_void, mut uc: u8, n: usize) -> Result<(), CUresult> {
     GlobalState::lock_stream(stream::CU_STREAM_LEGACY, |stream| {
         let cmd_list = stream.command_list()?;
         unsafe {
-            cmd_list.append_memory_fill_unsafe(dst, &uc, mem::size_of::<u8>() * n, None, &mut [])
+            cmd_list.append_memory_fill_raw(
+                dst,
+                &mut uc as *mut _ as *mut _,
+                mem::size_of::<u8>(),
+                mem::size_of::<u8>() * n,
+                None,
+                &mut [],
+            )
         }?;
         stream.queue.execute_and_synchronize(cmd_list)?;
         Ok::<_, CUresult>(())