我从 here 得到代码.
class Timer {
public:
Timer();
};
class TimeKeeper {
public:
TimeKeeper(const Timer& t);
int get_time()
{
return 1;
}
};
int main() {
TimeKeeper time_keeper(Timer());
return time_keeper.get_time();
}
从它的外观来看,它应该由于以下行而出现编译错误:
TimeKeeper time_keeper(Timer());
但只有 return time_keeper.get_time();
存在时才会发生。
为什么这一行会很重要,编译器会发现 time_keeper(Timer() )
构造中的歧义。
最佳答案
这是因为 TimeKeeper time_keeper(Timer());
被解释为函数声明而不是变量定义。这本身并不是错误,但是当您尝试访问 time_keeper 的 get_time()
成员(这是一个函数,而不是 TimeKeeper 实例)时,您的编译器会失败。
这是您的编译器查看代码的方式:
int main() {
// time_keeper gets interpreted as a function declaration with a function argument.
// This is definitely *not* what we expect, but from the compiler POV it's okay.
TimeKeeper time_keeper(Timer (*unnamed_fn_arg)());
// Compiler complains: time_keeper is function, how on earth do you expect me to call
// one of its members? It doesn't have member functions!
return time_keeper.get_time();
}
关于c++ - 最烦人的解析,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31225809/