结构中的枚举 - C 与 C++
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/23462307/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Enumerations within a struct - C vs C++
提问by arunmoezhi
I'm trying to use Enums within a struct, this compiles and works fine with gcc.
But the same code when compiled with g++throws an error.
我正在尝试在结构中使用枚举，这可以编译并与gcc. 但是编译时相同的代码g++会引发错误。
#include<stdio.h>
#include<stdlib.h>
struct foo
{
enum {MODE1, MODE2, MODE3} mode;
enum {TYPE1, TYPE2} type;
};
void bar(struct foo* bar)
{
bar->mode = MODE1;
}
int main()
{
struct foo* foo = (struct foo*) malloc(sizeof(struct foo));
bar(foo);
printf("mode=%d\n",foo->mode);
}
Output obtained with gcc:
获得的输出gcc：
$ gcc foo.c
$ ./a.out
mode=0
Output obtained with g++:
获得的输出g++：
$ g++ foo.c
foo.c: In function ‘void bar(foo*)':
foo.c:11: error: ‘MODE1' was not declared in this scope
回答by juanchopanza
MODE1is in the scope of foo, so you need
MODE1在 的范围内foo，所以你需要
bar->mode = foo::MODE1;
Note that if you want to access the enum types without a scope, you would need to declare them so. For example:
请注意，如果您想在没有作用域的情况下访问枚举类型，则需要如此声明它们。例如：
typedef enum {MODE1, MODE2, MODE3} MODE;
typedef enum {TYPE1, TYPE2} TYPE;
struct foo
{
MODE mode;
TYPE type;
};
