Relax the requirements on CustomOp. (#486)

* Relax the requirements on CustomOp.

* Simplify the custom-ops when no backward is required.

1 files changed, 15 insertions, 6 deletions

diff --git a/candle-core/src/op.rs b/candle-core/src/op.rs
index 2b57f7f7..cf99f86e 100644
--- a/candle-core/src/op.rs
+++ b/candle-core/src/op.rs
@@ -118,13 +118,22 @@ pub enum Op {
     ToDevice(Tensor),
     Transpose(Tensor, usize, usize),
     Elu(Tensor, f64),
-    CustomOp1(Tensor, std::sync::Arc<Box<dyn CustomOp1>>),
-    CustomOp2(Tensor, Tensor, std::sync::Arc<Box<dyn CustomOp2>>),
-    CustomOp3(Tensor, Tensor, Tensor, std::sync::Arc<Box<dyn CustomOp3>>),
+    CustomOp1(Tensor, std::sync::Arc<Box<dyn CustomOp1 + Send + Sync>>),
+    CustomOp2(
+        Tensor,
+        Tensor,
+        std::sync::Arc<Box<dyn CustomOp2 + Send + Sync>>,
+    ),
+    CustomOp3(
+        Tensor,
+        Tensor,
+        Tensor,
+        std::sync::Arc<Box<dyn CustomOp3 + Send + Sync>>,
+    ),
 }
 
 /// Unary ops that can be defined in user-land.
-pub trait CustomOp1: Send + Sync {
+pub trait CustomOp1 {
     // Box<dyn> does not support const yet, so use a function to get the name.
     fn name(&self) -> &'static str;
 
@@ -148,7 +157,7 @@ pub trait CustomOp1: Send + Sync {
     }
 }
 
-pub trait CustomOp2: Send + Sync {
+pub trait CustomOp2 {
     fn name(&self) -> &'static str;
 
     /// The forward pass, as run on a cpu device. Note that the storage can use arbitrary strides,
@@ -186,7 +195,7 @@ pub trait CustomOp2: Send + Sync {
     }
 }
 
-pub trait CustomOp3: Send + Sync {
+pub trait CustomOp3 {
     fn name(&self) -> &'static str;
 
     /// The forward pass, as run on a cpu device. Note that the storage can use arbitrary strides,