void*指针的一些冷知识

最新推荐文章于 2025-09-12 18:45:12 发布

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最新推荐文章于 2025-09-12 18:45:12 发布

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原文链接：http://www.cnblogs.com/sunfishgao/p/4762177.html

本文详细解释了在C/C++中void指针的算术运算原理。由于void指针没有固定大小，通常不能直接进行加减操作。但在GCC等编译器中，可以通过非标准扩展实现，将void指针视作char*类型进行字节级别的加减操作。

Pointer (computer programming)
Pointer arithmetic cannot be performed on void pointers because the void type has no size, and thus the pointed address can not be added to, although gcc and other compilers will perform byte arithmetic on void* as a non-standard extension, treating it as if it were char *.

Pointer Arith
In GNU C, addition and subtraction operations are supported on pointers to void and on pointers to functions. This is done by treating the size of a void or of a function as 1.

so...sizeof(void *) = sizeof(char *) = 4.

by the way, sizeof(char) = 1.

如果一个变量point的类型是void*,他在point++ ，point = point + 1 等操作的时候，是往下数1个字节。因为void*会被默认当作char*

转载于:https://www.cnblogs.com/sunfishgao/p/4762177.html