gpu: add QuerySet.Descriptor.init slice helper

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

gpu/README.md

@@ -171,6 +171,7 @@ And, to initialize data structures with slices in them, the following helpers ar
 * `TogglesDeviceDescriptor.init`
 * `Device.Descriptor.init`
 * `PipelineLayout.Descriptor.init`
+* `QuerySet.Descriptor.init`
 
 ### Typed callbacks
 

gpu/src/query_set.zig

@@ -9,9 +9,26 @@ pub const QuerySet = opaque {
         label: ?[*:0]const u8 = null,
         type: QueryType,
         count: u32,
-        // TODO: slice helper
         pipeline_statistics: ?[*]const PipelineStatisticName = null,
         pipeline_statistics_count: u32 = 0,
+
+        /// Provides a slightly friendlier Zig API to initialize this structure.
+        pub inline fn init(v: struct {
+            next_in_chain: ?*const ChainedStruct = null,
+            label: ?[*:0]const u8 = null,
+            type: QueryType,
+            count: u32,
+            pipeline_statistics: ?[]const PipelineStatisticName = null,
+        }) Descriptor {
+            return .{
+                .next_in_chain = v.next_in_chain,
+                .label = v.label,
+                .type = v.type,
+                .count = v.count,
+                .pipeline_statistics_count = if (v.pipeline_statistics) |e| @intCast(u32, e.len) else 0,
+                .pipeline_statistics = if (v.pipeline_statistics) |e| e.ptr else null,
+            };
+        }
     };
 
     pub inline fn destroy(query_set: *QuerySet) void {