1export fn a() void {
 2    const S = struct { x: i32, y: i32 };
 3    var s: S = undefined;
 4    s[0] = 10;
 5}
 6
 7// error
 8//
 9// :4:6: error: type 'tmp.a.S' does not support indexing
10// :4:6: note: operand must be an array, slice, tuple, or vector