我应该使用static_cast或reinterpret_cast当投射一个void *任何东西 [英] Should I use static_cast or reinterpret_cast when casting a void* to whatever

问题描述

static_cast和reinterpret_cast似乎都可以很好地将void *转换为另一个指针类型。

Both static_cast and reinterpret_cast seem to work fine for casting void* to another pointer type. Is there a good reason to favor one over the other?

推荐答案

您应该使用 reinterpret_cast ，因为它能更好地描述您正在做什么（完全忽略类型安全）

You should use a reinterpret_cast, because that describes better what you're doing (completely ignoring type safety)

这实际上不是描述 reinterpret_cast 的效果。相反， reinterpret_cast 有许多含义，对于所有这些都认为 reinterpret_cast 定义。[5.2.10.3]

This does actually not describe the effect of a reinterpret_cast. Rather, reinterpret_cast has a number of meanings, for all of which holds that "the mapping performed by reinterpret_cast is implementation-defined." [5.2.10.3]

但是，这不是在这种特殊情况下会发生什么，

However, this is not what happens in this particular case, where the mapping is well-defined by the standard, namely assigning a type to a typeless pointer without changing its address.

这是一个更喜欢 static_cast 。

此外，更重要的是，每次使用 reinterpret_cast 都是危险的，因为它将任何内容转换为其他任何东西（对于指针），而 static_cast 则限制性更强，从而提供更好的保护级别。这已经救了我从错误，我不小心试图强制一种指针类型到另一个。

Additionally, and arguably more important, is the fact that every use of reinterpret_cast is downright dangerous because it converts anything to anything else really (for pointers), while static_cast is much more restrictive, thus providing a better level of protection. This has already saved me from bugs where I accidentally tried to coerce one pointer type into another.

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