Add TryClone trait

src/index/flat.rs

@@ -144,15 +144,16 @@ impl TryFromInnerPtr for FlatIndexImpl {
 
 impl_native_index!(FlatIndex);
 
-impl_native_index_clone!(FlatIndex);
+impl TryClone for FlatIndexImpl {}
 
 impl_concurrent_index!(FlatIndexImpl);
 
 #[cfg(test)]
 mod tests {
     use super::FlatIndexImpl;
     use crate::index::{
-        index_factory, ConcurrentIndex, FromInnerPtr, Idx, Index, NativeIndex, UpcastIndex,
+        index_factory, ConcurrentIndex, FromInnerPtr, Idx, Index, NativeIndex, TryClone,
+        UpcastIndex,
     };
     use crate::metric::MetricType;
 

src/index/ivf_flat.rs

@@ -142,7 +142,7 @@ impl FromInnerPtr for IVFFlatIndexImpl {
 
 impl_native_index!(IVFFlatIndex);
 
-impl_native_index_clone!(IVFFlatIndex);
+impl TryClone for IVFFlatIndexImpl {}
 
 impl_concurrent_index!(IVFFlatIndexImpl);
 

src/index/lsh.rs

@@ -2,7 +2,7 @@
 
 use super::{
     AssignSearchResult, CpuIndex, FromInnerPtr, Idx, Index, IndexImpl, NativeIndex,
-    RangeSearchResult, SearchResult, TryFromInnerPtr,
+    RangeSearchResult, SearchResult, TryClone, TryFromInnerPtr,
 };
 use crate::error::{Error, Result};
 use crate::faiss_try;
@@ -110,7 +110,7 @@ impl LshIndex {
 
 impl_native_index!(LshIndex);
 
-impl_native_index_clone!(LshIndex);
+impl TryClone for LshIndex {}
 
 impl IndexImpl {
     /// Attempt a dynamic cast of an index to the LSH index type.

src/index/mod.rs

@@ -322,6 +322,26 @@ pub trait TryFromInnerPtr: NativeIndex {
         Self: Sized;
 }
 
+/// A macro which provides a Clone implementation to native index types.
+pub trait TryClone: FromInnerPtr {
+    /// Create an independent clone of this index.
+    ///
+    /// # Errors
+    ///
+    /// May result in a native error if the clone operation is not
+    /// supported for the internal type of index.
+    fn try_clone(&self) -> Result<Self>
+    where
+        Self: Sized,
+    {
+        unsafe {
+            let mut new_index_ptr = ::std::ptr::null_mut();
+            faiss_try(faiss_clone_index(self.inner_ptr(), &mut new_index_ptr))?;
+            Ok(crate::index::FromInnerPtr::from_inner_ptr(new_index_ptr))
+        }
+    }
+}
+
 /// The outcome of an index assign operation.
 #[derive(Debug, Clone, PartialEq)]
 pub struct AssignSearchResult {
@@ -468,7 +488,7 @@ impl TryFromInnerPtr for IndexImpl {
 }
 
 /// Index upcast trait.
-/// 
+///
 /// If you need to store several different types of indexes in one collection,
 /// you can cast all indexes to the common type `IndexImpl`.
 /// # Examples
@@ -499,7 +519,7 @@ impl<NI: NativeIndex> UpcastIndex for NI {
 
 impl_native_index!(IndexImpl);
 
-impl_native_index_clone!(IndexImpl);
+impl TryClone for IndexImpl {}
 
 /// Use the index factory to create a native instance of a Faiss index, for `d`-dimensional
 /// vectors. `description` should follow the exact guidelines as the native Faiss interface
@@ -530,7 +550,7 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::{index_factory, Idx, Index};
+    use super::{index_factory, Idx, Index, TryClone};
     use crate::metric::MetricType;
 
     #[test]

src/index/pretransform.rs

@@ -218,21 +218,7 @@ impl<I> Index for PreTransformIndexImpl<I> {
     }
 }
 
-impl<I> PreTransformIndexImpl<I> {
-    /// Create an independent clone of this index.
-    ///
-    /// # Errors
-    ///
-    /// May result in a native error if the clone operation is not
-    /// supported for the internal type of index.
-    pub fn try_clone(&self) -> Result<Self> {
-        unsafe {
-            let mut new_index_ptr = ::std::ptr::null_mut();
-            faiss_try(faiss_clone_index(self.inner_ptr(), &mut new_index_ptr))?;
-            Ok(crate::index::FromInnerPtr::from_inner_ptr(new_index_ptr))
-        }
-    }
-}
+impl<I: TryClone> TryClone for PreTransformIndexImpl<I> {}
 
 impl<I> ConcurrentIndex for PreTransformIndexImpl<I>
 where

src/index/refine_flat.rs

@@ -200,21 +200,7 @@ impl<BI> Index for RefineFlatIndexImpl<BI> {
     }
 }
 
-impl<BI> RefineFlatIndexImpl<BI> {
-    /// Create an independent clone of this index.
-    ///
-    /// # Errors
-    ///
-    /// May result in a native error if the clone operation is not
-    /// supported for the internal type of index.
-    pub fn try_clone(&self) -> Result<Self> {
-        unsafe {
-            let mut new_index_ptr = ::std::ptr::null_mut();
-            faiss_try(faiss_clone_index(self.inner_ptr(), &mut new_index_ptr))?;
-            Ok(crate::index::FromInnerPtr::from_inner_ptr(new_index_ptr))
-        }
-    }
-}
+impl<BI: TryClone> TryClone for RefineFlatIndexImpl<BI> {}
 
 impl<BI> ConcurrentIndex for RefineFlatIndexImpl<BI>
 where

src/index/scalar_quantizer.rs

@@ -105,7 +105,7 @@ impl FromInnerPtr for ScalarQuantizerIndexImpl {
 
 impl_native_index!(ScalarQuantizerIndexImpl);
 
-impl_native_index_clone!(ScalarQuantizerIndexImpl);
+impl TryClone for ScalarQuantizerIndexImpl {}
 
 impl IndexImpl {
     /// Attempt a dynamic cast of an index to the Scalar Quantizer index type.
@@ -403,21 +403,7 @@ impl<Q> Index for IVFScalarQuantizerIndexImpl<Q> {
     }
 }
 
-impl<Q> IVFScalarQuantizerIndexImpl<Q> {
-    /// Create an independent clone of this index.
-    ///
-    /// # Errors
-    ///
-    /// May result in a native error if the clone operation is not
-    /// supported for the internal type of index.
-    pub fn try_clone(&self) -> Result<Self> {
-        unsafe {
-            let mut new_index_ptr = ::std::ptr::null_mut();
-            faiss_try(faiss_clone_index(self.inner_ptr(), &mut new_index_ptr))?;
-            Ok(crate::index::FromInnerPtr::from_inner_ptr(new_index_ptr))
-        }
-    }
-}
+impl<Q: TryClone> TryClone for IVFScalarQuantizerIndexImpl<Q> {}
 
 impl<Q> ConcurrentIndex for IVFScalarQuantizerIndexImpl<Q>
 where

src/macros.rs

@@ -176,27 +176,6 @@ macro_rules! impl_native_index {
     };
 }
 
-/// A macro which provides a Clone implementation to native index types.
-macro_rules! impl_native_index_clone {
-    ($t:ty) => {
-        impl $t {
-            /// Create an independent clone of this index.
-            ///
-            /// # Errors
-            ///
-            /// May result in a native error if the clone operation is not
-            /// supported for the internal type of index.
-            pub fn try_clone(&self) -> Result<Self> {
-                unsafe {
-                    let mut new_index_ptr = ::std::ptr::null_mut();
-                    faiss_try(faiss_clone_index(self.inner_ptr(), &mut new_index_ptr))?;
-                    Ok(crate::index::FromInnerPtr::from_inner_ptr(new_index_ptr))
-                }
-            }
-        }
-    };
-}
-
 /// A macro which provides a concurrent index implementation to the given type.
 macro_rules! impl_concurrent_index {
     ($t:ty) => {