为什么我们在 C++ 中没有虚拟构造函数?

2021-12-30 00:00:00 constructor c++ virtual-functions

为什么 C++ 没有虚构造函数?

Why does C++ not have a virtual constructor?

推荐答案

听马的.:)

来自 Bjarne Stroustrup 的 C++ 风格和技术常见问题解答 为什么我们没有虚拟构造函数?

From Bjarne Stroustrup's C++ Style and Technique FAQ Why don't we have virtual constructors?

虚拟调用是一种在给定部分的情况下完成工作的机制信息.特别是,虚拟"允许我们调用一个函数只知道任何接口,而不知道对象的确切类型.到创建对象需要完整的信息.特别是你需要知道您要创建的确切类型.最后,对构造函数的调用"不能是虚拟的.

A virtual call is a mechanism to get work done given partial information. In particular, "virtual" allows us to call a function knowing only any interfaces and not the exact type of the object. To create an object you need complete information. In particular, you need to know the exact type of what you want to create. Consequently, a "call to a constructor" cannot be virtual.

FAQ 条目继续提供无需虚拟构造函数即可实现此目的的方法的代码.

The FAQ entry goes on to give the code for a way to achieve this end without a virtual constructor.

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