是否有可能定义将在构造函数中用作默认参数的变量?
#include <iostream>
class Foo
{
public:
Foo(int x) { num = x;}
void print(int y = num)
{
std::cout << y << std::endl;
}
private:
static int num;
};
int main()
{
Foo f(5);
f.print();
}
此编译,但出现链接错误LNK2001 unresolved external symbol "private: static int Foo::num" (?num@Foo@@0HA)
有可能,您只需要在类外声明/初始化静态变量: