dart / co19 / 71951f8d687c6e7400bc9e5605301d2ef3fafa5b / . / LanguageFeatures / Set-literals / type_inference_A26_t02.dart

/* | |

* Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file | |

* for details. All rights reserved. Use of this source code is governed by a | |

* BSD-style license that can be found in the LICENSE file. | |

*/ | |

/** | |

* @assertion Finally, we define inference on a setOrMapLiteral collection as | |

* follows: | |

* ... | |

* Otherwise, collection is still ambiguous, the downwards context for the | |

* elements of collection is ?, and the disambiguation is done using the | |

* immediate elements of collection as follows: | |

* | |

* If all elements can be a set, and at least one element must be a set, then | |

* collection is a set literal with static type Set<T> where T is the least | |

* upper bound of the set element types of the elements. | |

* | |

* @description Checks that if all elements can be a set, and at least one | |

* element must be a set, then collection is a set literal with static type | |

* Set<T> where T is the least upper bound of the set element types of the | |

* elements | |

* @author sgrekhov@unipro.ru | |

*/ | |

import "../../Utils/expect.dart"; | |

main() { | |

dynamic d = [1, 2, 3]; | |

var s1 = {...d, 4}; | |

Expect.isTrue(s1 is Set<dynamic>); | |

Expect.isFalse(s1 is Set<int>); | |

var s2 = {...?d, 4}; | |

Expect.isTrue(s2 is Set<dynamic>); | |

Expect.isFalse(s2 is Set<int>); | |

} |