diff --git a/src/lib.zig b/src/lib.zig
index 6277955202d6eea8c49ef586cd88200c48366ad6..eb2f1eb8fa180ffd76e20ede29cf8e46ccd5f3ef 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -376,3 +376,11 @@ pub fn readType(reader: anytype, comptime T: type, endian: std.builtin.Endian) !
         else => |e| @compileError(@tagName(e)),
     };
 }
+
+pub fn indexBufferT(bytes: []const u8, comptime T: type, endian: std.builtin.Endian, idx: usize, max_len: usize) T {
+    std.debug.assert(idx < max_len);
+    var fbs = std.io.fixedBufferStream(bytes[idx * (@sizeOf(T) / @sizeOf(u8)) ..]);
+    return readType(fbs.reader(), T, endian) catch |err| switch (err) {
+        error.EndOfStream => unreachable, // assert above has been violated
+    };
+}