add metal support

Cargo.toml

@@ -36,6 +36,7 @@ rayon = "1.10"
 [features]
 flash-attn=["candle-flash-attn"]
 cuda=["candle-nn/cuda", "candle-core/cuda", "candle-transformers/cuda"]
+metal=["candle-nn/metal", "candle-core/metal", "candle-transformers/metal"]
 ffmpeg=["ffmpeg-next"]
 
 [lints.clippy]

src/utils/mod.rs

@@ -27,7 +27,11 @@ pub fn get_device(device: Option<&Device>) -> Device {
             {
                 Device::new_cuda(0).unwrap_or(Device::Cpu)
             }
-            #[cfg(not(feature = "cuda"))]
+            #[cfg(all(not(feature = "cuda"), feature = "metal"))]
+            {
+                Device::new_metal(0).unwrap_or(Device::Cpu)
+            }
+            #[cfg(all(not(feature = "cuda"), not(feature = "metal")))]
             {
                 Device::Cpu
             }