无法从“const char [3]"转换为“char *"x100000(Qt Creator C++ Windows 32) [英] cannot convert from 'const char [3]' to 'char *' x100000 (Qt Creator C++ Windows 32)

问题描述

就在五分钟前，当我点击 f5 并出现 102 个错误时，一切正常:

Everything was working fine just five minutes ago when I tapped f5 and got 102 errors:

error: C2440: 'initializing' : cannot convert from 'const char [17]' to 'char *'
Conversion from string literal loses const qualifier (see /Zc:strictStrings)

那个特定的在第 30 行:

That specific one is at line 30:

char* hexchars = "0123456789ABCDEF";

我至少一个星期没有碰过错误所在的文件.我通常会说我不小心更改了编译参数或其他东西，但在它开始出错之前我没有打开设置.

I haven't touched the file the errors are in for at least a week. I'd normally say I accidentally changed something in the compile args or something, but I haven't opened settings since much before it started erroring.

有什么想法吗?我一定是心不在焉地改变了一些设置，但我真的不记得想过呃，我刚刚做了什么?"

Any ideas? I must have absentmindedly changed some setting but I really can't remember thinking "uh oh what did I just do?"

推荐答案

当你使用这样的代码时

char *astring2 = "some letters";

C++(和 C)将其放入只读内存中.您不能修改用文字初始化的 char 指针的内容，即使它不是 const.

C++ (and C) puts that into read only memory. You can not modify the contents of a char pointer initialized with a literal even if it is not const.

同样你也不能改变指针的地址，因为上面的规则会导致内存泄漏.

Also you can not change the address of the pointer because it will cause a memory leak due to the rule above.

但是，除非您将其设置为 const，否则这不符合该规则:

This, however, does not follow that rule UNLESS you make it const:

char astring[] = "some letters that can be changed";
char *ptrToString = astring; //work
astring2 = astring //not work

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