Question

如果我宣布一个有违约构造的班级,并界定一个有初步设计人名单的班级,那么将要求违约施工人作出这一定义吗? 为什么有人被称作或没有被称作?

class Sample
{
// this should be any aggregate type in c++
};

int main()
{
  Sample s = {0};
  return 0;
}

Answer 1

标准说(8。5/14)

初始动力的特性如下。目的地类型是标的类型或标注的类型,来源类型是初始表达器的类型。原始器具被掩蔽或作为母体表示清单时,对来源类型未作界定。

If the destination type is a (possibly cv-qualified) class type: — If the class is an aggregate (8。5。1), and the initializer is a brace-enclosed list, see 8。5。1。。

。

8。5。1/13

[Note: An aggregate array or an aggregate class may contain members of a class type with a user-declared constructor (12。1)。 Initialization of these aggregate objects is described in 12。6。1。 ]

Also 12。6。1/2 says

When an aggregate (whether class or array) contains members of class type and is initialized by a brace-enclosed initializer-list (8。5。1), each such member is copy-initialized (see 8。5) by the corresponding assignment-expression。 If there are fewer initializers in the initializer-list than members of the aggregate, each member not explicitly initialized shall be value-initialized (8。5)。

Answer 2

In C++03, only aggregate classes may be initialized with curly braces, and an aggregate class may not have a user defined constructor
In C++0x, this syntax is supported for non aggregate types through initializer lists and calls the appropriate constructor (taking a std::initializer_list)

Answer 3

当你提供一种装饰的原始器时,该类所有成员均从被掩饰的原始器的相应表述中录出。

这种初始化只适用于无法拥有用户申报的建筑商的聚合物,因此压制编造者几乎是学术性的。

Answer 4

The corresponding constructor is called: http://en.wikipedia.org/wiki/C%2B%2B0x#Initializer_lists

Answer 5

在C++中,你只能先把POD(解释旧数据)设定为={0}(至少在C++0x之前)。因此,将不要求违约的建筑商,因为这套建筑群集了起来。

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