feat(channel): impl peek()

src/lib.zig

@@ -78,6 +78,16 @@ fn Channel(comptime T: type) type {
             return value;
         }
 
+        pub fn peek(self: *const Self) ?T {
+            const read_idx = self.read.load(.Acquire);
+            const write_idx = self.write.load(.Acquire);
+
+            if (read_idx == write_idx) return null;
+
+            std.atomic.fence(.Acquire);
+            return self.buf[self.mask(read_idx)];
+        }
+
         pub fn len(self: *const Self) Index {
             const read_idx = self.read.load(.Acquire);
             const write_idx = self.write.load(.Acquire);