在malloc的C，而是用多维数组语法 [英] malloc in C, but use multi-dimensional array syntax

问题描述

有没有办法到malloc的大阵，而是指它与2D语法？我想是这样的：

Is there any way to malloc a large array, but refer to it with 2D syntax? I want something like:

int *memory = (int *)malloc(sizeof(int)*400*200);
int MAGICVAR = ...;
MAGICVAR[20][10] = 3; //sets the (200*20 + 10)th element

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更新：这是必须提到：我只是想有一个内存连续块。我只是不想写这样一个宏：

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UPDATE: This was important to mention: I just want to have one contiguous block of memory. I just don't want to write a macro like:

#define INDX(a,b) (a*200+b);

再参考我的斑点，如：

and then refer to my blob like:

memory[INDX(a,b)];

我更preFER：

I'd much prefer:

memory[a][b];

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更新：据我所知，编译器无法知道原样方式。我愿意提供额外的信息，是这样的：

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UPDATE: I understand the compiler has no way of knowing as-is. I'd be willing to supply extra information, something like:

int *MAGICVAR[][200] = memory;

这样没有语法是否存在？请注意，我不只是使用一个固定宽度数组的原因是，它太大了放置在堆栈中。

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更新：好，大家好，我可以这样做：

Does no syntax like this exist? Note the reason I don't just use a fixed width array is that it is too big to place on the stack.

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UPDATE: OK guys, I can do this:

void toldyou(char MAGICVAR[][286][5]) {
  //use MAGICVAR
}

//from another function:
  char *memory = (char *)malloc(sizeof(char)*1820*286*5);
  fool(memory);

我得到一个警告，从兼容的指针类型，而code ++工程，通过ARG 1 toldyou，我已经验证了在同一地点进行访问。有没有办法做到这一点，而不使用其他功能？

I get a warning, passing arg 1 of toldyou from incompatible pointer type, but the code works, and I've verified that the same locations are accessed. Is there any way to do this without using another function?

推荐答案

是的，你可以做到这一点，并没有像大多数其他的答案都告诉你，你不需要指针的另一个数组。你要调用仅仅是：

Yes, you can do this, and no, you don't need another array of pointers like most of the other answers are telling you. The invocation you want is just:

int (*MAGICVAR)[200] = malloc(400 * sizeof *MAGICVAR);
MAGICVAR[20][10] = 3; // sets the (200*20 + 10)th element

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