错误:在指定类型“void *”类型的“值”时，不兼容的类型?

I get this error when I'm trying to malloc some memory for my struct of ints.

当我试图对ints的结构进行malloc的一些内存时，我就会得到这个错误。

typedef struct _values {
random ints;
} values;

I have tried the lines below but my compiler doesn't like it. How do I fix the error?

我试过下面的行，但我的编译器不喜欢。我如何修正错误?

values v;
v = malloc(sizeof(values));

3 个解决方案

#1

You forgot to add the asterisk (*) after the values and before the v to mark it as a pointer: values *v;

您忘记在值和v之前添加星号(*)，将其标记为指针:values *v;

The way you set it now, the v (without the asterisk) is defined as a stack variable and would be allocated on the stack and discarded once the function ends. It's type will be simply values. malloc is used to allocate memory on the heap and returns a pointer to the memory. Sine the function has no way of knowing the type it returns it as a void * type - Which gives you your error - you're attempting to assign a void * type into a struct type, which the compiler can't do, nor can the compiler find a legitimate cast that could resolve the problem.

现在设置它的方式是，v(没有星号)被定义为一个堆栈变量，并在函数结束时被分配到堆栈上并丢弃。它的类型就是简单的值。malloc用于在堆上分配内存，并返回一个指向内存的指针。正弦函数没有办法知道它返回类型为void *类型——给你你的错误——你试图分配一个void *类型到一个结构体类型,编译器不能做,编译器也不能找一个合法的可以解决问题。

#2

You don't need to malloc memory in this case; the line values v; already allocated the memory ("on the stack"). It will automatically be freed when you leave the current scope.

在这种情况下，您不需要malloc内存;行值v;已经分配了内存(“在堆栈上”)。当您离开当前的范围时，它将自动释放。

If you really wanted to allocate the memory "on the heap", so that it persists past the current scope, you need v to be a pointer; that is:

如果您真的想要将内存分配到“堆”上，那么它就会在当前范围内存在，您需要v作为指针;那就是:

values *v;
v = malloc(sizeof(values));

Remember to free it when you're finished.

记住当你完成的时候把它释放出来。

#3

values v;

值v;

this is an instance of the structure that's allocated on the stack.

这是在堆栈上分配的结构的实例。

v = malloc(sizeof(values));

v = malloc(sizeof(值));

malloc returns a void* pointer and compiler won't allow you to assign a pointer to an instance.

malloc返回一个void*指针，编译器不允许你分配一个指向实例的指针。

you need to declare a pointer and then assign the malloc return pointer to it.

您需要声明一个指针，然后分配malloc返回指针。

something of the sort

类似的意思

values *v = NULL;

值* v =零;

v = malloc(sizeof(values));

#1