diff --git a/src/buffer/num.rs b/src/buffer/num.rs
index 6813ce9f..cf2d1bde 100644
--- a/src/buffer/num.rs
+++ b/src/buffer/num.rs
@@ -27,6 +27,9 @@ impl<T> PtrType for Num<T> {
     fn flag(&self) -> crate::flag::AllocFlag {
         crate::flag::AllocFlag::Num
     }
+
+    #[inline]
+    unsafe fn set_flag(&mut self, _flag: AllocFlag) {}
 }
 
 impl<T> CommonPtrs<T> for Num<T> {
diff --git a/src/device_traits.rs b/src/device_traits.rs
index 9fca3e89..0ed98a77 100644
--- a/src/device_traits.rs
+++ b/src/device_traits.rs
@@ -1,7 +1,5 @@
 // TODO: move to devices folder ig
 
-use core::ops::Deref;
-
 use crate::{flag::AllocFlag, prelude::Device, Buffer, HasId, Parents, PtrType, Shape, StackArray};
 
 pub trait Alloc<T>: Device + Sized {
diff --git a/src/devices/cpu/cpu_device.rs b/src/devices/cpu/cpu_device.rs
index d89f7780..5e3936ac 100644
--- a/src/devices/cpu/cpu_device.rs
+++ b/src/devices/cpu/cpu_device.rs
@@ -8,7 +8,7 @@ use crate::{
     cpu::CPUPtr, flag::AllocFlag, impl_buffer_hook_traits, impl_retriever, pass_down_grad_fn,
     pass_down_optimize_mem_graph, pass_down_tape_actions, Alloc, Base, Buffer, CloneBuf, Device,
     DevicelessAble, HasModules, Module, OnDropBuffer, OnNewBuffer, PtrConv, Setup, Shape,
-    WrappedData,
+    WrappedData, PtrType,
 };
 
 pub trait IsCPU {}
@@ -163,6 +163,7 @@ impl<Mods: OnDropBuffer, OtherMods: OnDropBuffer> PtrConv<CPU<OtherMods>> for CP
         data: &Mods::Wrap<CPUPtr<T>>,
         flag: AllocFlag,
     ) -> OtherMods::Wrap<CPUPtr<Conv>> {
+        // data.flag()
         todo!()
         // CPUPtr {
         //     ptr: data.ptr as *mut Conv,
diff --git a/src/devices/cpu/cpu_ptr.rs b/src/devices/cpu/cpu_ptr.rs
index 79c9ba8e..44391674 100644
--- a/src/devices/cpu/cpu_ptr.rs
+++ b/src/devices/cpu/cpu_ptr.rs
@@ -207,6 +207,11 @@ impl<T> PtrType for CPUPtr<T> {
     fn flag(&self) -> AllocFlag {
         self.flag
     }
+
+    #[inline]
+    unsafe fn set_flag(&mut self, flag: AllocFlag) {
+        self.flag = flag
+    }
 }
 
 impl<T> CommonPtrs<T> for CPUPtr<T> {
diff --git a/src/devices/cpu/ops.rs b/src/devices/cpu/ops.rs
index 5ff7afbf..7f93df85 100644
--- a/src/devices/cpu/ops.rs
+++ b/src/devices/cpu/ops.rs
@@ -11,8 +11,6 @@ use crate::{
 pass_down_add_operation!(CPU);
 pass_down_exec_now!(CPU);
 
-pub fn slice<T>(x: &[T]) {}
-
 impl<Mods, T, D, S> ApplyFunction<T, S, D> for CPU<Mods>
 where
     Mods: Retrieve<Self, T> + AddOperation + 'static,
diff --git a/src/devices/stack_array.rs b/src/devices/stack_array.rs
index a247a784..89f668db 100644
--- a/src/devices/stack_array.rs
+++ b/src/devices/stack_array.rs
@@ -120,6 +120,9 @@ impl<S: Shape, T> PtrType for StackArray<S, T> {
     fn flag(&self) -> crate::flag::AllocFlag {
         crate::flag::AllocFlag::None
     }
+
+    #[inline]
+    unsafe fn set_flag(&mut self, _flag: crate::flag::AllocFlag) {}
 }
 
 impl<S: Shape, T> CommonPtrs<T> for StackArray<S, T> {
diff --git a/src/lib.rs b/src/lib.rs
index 69432146..202b4f81 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -144,6 +144,7 @@ pub trait PtrType {
     fn size(&self) -> usize;
     /// Returns the [`AllocFlag`].
     fn flag(&self) -> AllocFlag;
+    unsafe fn set_flag(&mut self, flag: AllocFlag);
 }
 
 pub trait HostPtr<T>: PtrType {
diff --git a/src/modules/lazy.rs b/src/modules/lazy.rs
index 2308027e..36300ec8 100644
--- a/src/modules/lazy.rs
+++ b/src/modules/lazy.rs
@@ -60,6 +60,11 @@ impl<Data: PtrType> PtrType for LazyWrapper<Data> {
     fn flag(&self) -> crate::flag::AllocFlag {
         self.data.flag()
     }
+
+    #[inline]
+    unsafe fn set_flag(&mut self, flag: crate::flag::AllocFlag) {
+        self.data.set_flag(flag)
+    }
 }
 
 impl<Data> Deref for LazyWrapper<Data> {
@@ -145,7 +150,7 @@ impl<D: LazySetup, Mods: Setup<D>> Setup<D> for Lazy<Mods> {
     }
 }
 
-impl<Mods: RunModule<D>, D: LazyRun + PtrConv + 'static> RunModule<D> for Lazy<Mods> {
+impl<Mods: RunModule<D>, D: LazyRun + Device + 'static> RunModule<D> for Lazy<Mods> {
     #[inline]
     fn run(&self, device: &D) -> crate::Result<()> {
         unsafe { self.call_lazily::<D>()? };