Precise descriptor set unit test

vulkan-rs/src/descriptorset.rs

@@ -347,7 +347,6 @@ mod test {
     use std::sync::Arc;
 
     #[test]
-
     fn create_multiple_sets_from_one_pool() -> Result<()> {
         const DESCRIPTOR_COUNT: u32 = 2;
 
@@ -367,11 +366,17 @@ mod test {
             .set_layout(descriptor_layout.clone())
             .build(device.clone())?;
 
-        let descriptors: Result<Vec<Arc<DescriptorSet>>> = (0..DESCRIPTOR_COUNT)
+        let descriptors: Vec<Arc<DescriptorSet>> = (0..DESCRIPTOR_COUNT)
-            .map(|_| descriptor_pool.prepare_set().allocate())
+            .map(|_| {
+                let set = descriptor_pool.prepare_set().allocate();
+
+                assert!(set.is_ok(), "{}", set.err().unwrap());
+
+                set.unwrap()
+            })
             .collect();
 
-        assert!(descriptors.is_ok(), "{}", descriptors.err().unwrap());
+        assert_eq!(descriptors.len(), DESCRIPTOR_COUNT as usize);
 
         Ok(())
     }

vulkan-rs/src/device.rs

@@ -1142,8 +1142,7 @@ impl Device {
         unsafe {
             let count = allocate_info.descriptorSetCount as usize;
 
-            let mut descriptor_sets = Vec::with_capacity(count);
+            let mut descriptor_sets = vec![VkDescriptorSet::NULL_HANDLE; count];
-            descriptor_sets.set_len(count);
 
             let result = self.device_functions.vkAllocateDescriptorSets(
                 self.device,