class A {}
class B extends A {}

var a: A;
var b: B;
var i: i32;
var f: f32;

assert(  a instanceof A );
assert(  b instanceof A );
assert(!(i instanceof A));
assert(!(f instanceof A));

assert(!(a instanceof B));
assert(  b instanceof B );
assert(!(i instanceof B));
assert(!(f instanceof B));

assert(!(a instanceof i32));
assert(!(b instanceof i32));
assert(  i instanceof i32 );
assert(!(f instanceof i32));

assert(!(a instanceof f32));
assert(!(b instanceof f32));
assert(!(i instanceof f32));
assert(  f instanceof f32 );

function isI32<T>(v: T): bool {
  // should eliminate non-applicable branches (see fixture)
  if (v instanceof i32) {
    return true;
  } else {
    return false;
  }
}

assert( isI32(0));
assert(!isI32(0.0));

// TODO: what about nullables?
// var an: A | null;
// var bn: B | null;
//
// assert(an instanceof A);
// assert(bn instanceof A);
//
// assert(!(an instanceof B));
// assert(bn instanceof B);