UniPC for diffusion sampling (#2684)

* feat: Add unipc multistep scheduler

* chore: Clippy and formatting

* chore: Update comments

* chore: Avoid unsafety in float ordering

* refactor: Update Scheduler::step mutability requirements

* fix: Corrector img2img

* chore: Update unipc ref link to latest diffusers release

* chore: Deduplicate float ordering

* fix: Panic when running with dev profile

1 files changed, 2 insertions, 2 deletions

diff --git a/candle-examples/examples/stable-diffusion/main.rs b/candle-examples/examples/stable-diffusion/main.rs
index b6585afa..ebf0bfcb 100644
--- a/candle-examples/examples/stable-diffusion/main.rs
+++ b/candle-examples/examples/stable-diffusion/main.rs
@@ -477,7 +477,7 @@ fn run(args: Args) -> Result<()> {
         ),
     };
 
-    let scheduler = sd_config.build_scheduler(n_steps)?;
+    let mut scheduler = sd_config.build_scheduler(n_steps)?;
     let device = candle_examples::device(cpu)?;
     if let Some(seed) = seed {
         device.set_seed(seed)?;
@@ -539,7 +539,7 @@ fn run(args: Args) -> Result<()> {
     };
 
     for idx in 0..num_samples {
-        let timesteps = scheduler.timesteps();
+        let timesteps = scheduler.timesteps().to_vec();
         let latents = match &init_latent_dist {
             Some(init_latent_dist) => {
                 let latents = (init_latent_dist.sample()? * vae_scale)?.to_device(&device)?;