不兼容的类型错误 [英] Incompatible type error

问题描述

#include<windows.h>
#include<stdio.h>
#include <ctype.h>
typedef struct ret
{
	long long memory;
	char* drive;
};
int main()
{
	struct ret total_memory;
	total_memory=size_show(GetLogicalDrives());
	return 0;
}
struct ret size_show(long int  n ) 
{
	struct ret to_func;
	long long ii;
	long int  i, k, andmask;
	char a[5]="E://";
	char c;
	printf("%d",strlen(a));
	printf("drives available\n");   
	for ( i = 32 ; i >= 0 ; i-- )  
	{   
		andmask = 1 << i;   
		k = n & andmask;
		if(k!=0)
		{
			k=i+65;
			printf("%c:\n",k);
		}
	}
	printf("drive you want to clear\n");
	scanf("%c",&c);
	a[0]=toupper(c);
	printf("%s.\n",a);
	printf("%d\n",strlen(a));
	i=strcmp("E://",a);
	printf("%d",i);
	k=GetDiskFreeSpaceEx(a,NULL,NULL,&ii);
	printf("%ld",k);
	printf("%ld",ii);
	to_func.memory=ii;
	strcpy(to_func.drive,a);
	return to_func;
} 

我无法弄清楚上面的代码有什么问题，我希望从中返回两个值函数因此我使用结构，我期待代码中的警告而不是错误。

感谢您提前的帮助



< b>我尝试了什么：



我尝试更改数据类型

I can't figure out the problem the above code has, I want two values to be returned from the function hence I am using a struct, I was expecting warnings in the code instead getting errors.
Thanks for your help in advance

What I have tried:

I tried changing types of the data

推荐答案

一个函数不能返回一个结构，最多它可以返回一个指向结构的指针。

第二个问题，那个结构不能像你那样在堆栈上创建。

以下是一些讲座：

C编程语言 - 维基百科，免费的百科全书 [ ^ ]

HT tps：//hassanolity.files.wordpress.com/2013/11/the_c_programming_language_2.pdf [ ^ ]

http://www.ime.usp.br/~pf/Kernighan-Ritchie/C-Programming-Ebook.pdf [ ^ ]

A function can't return a structure, at best it can return a pointer to the structure.
Second problem, that structure can't be created on stack like you have done.
Here is some lecture:
The C Programming Language - Wikipedia, the free encyclopedia[^]
https://hassanolity.files.wordpress.com/2013/11/the_c_programming_language_2.pdf[^]
http://www.ime.usp.br/~pf/Kernighan-Ritchie/C-Programming-Ebook.pdf[^]

    struct ret to_func;
// ...
    strcpy(to_func.drive,a);

您在函数 size_show 的顶部声明了您的结构，但您从未初始化它。因此，当您尝试将某些内容复制到 to_func.drive 时，它会失败，因为您有一个未初始化的指针。



另外你的驱动器规格是错误的，你使用双正斜杠而不是反斜杠，应该E：\\。



如果您告诉我们哪行代码会出错，这会有所帮助。

You declare your struct at the top of the function size_show, but you never initialise it. So when you try to copy something to to_func.drive it fails because you have an uninitialised pointer.

Also your drive specifications are wrong, you are using double forward slashes instead of backslashes, should be "E:\\".

And it would help if you told us which line of code gives the error.

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