Do nested structs affect performance?

Question

If the nested struct will contain only static constant members, will it affect performance anyhow? I want to use it to scope these constants.

class File {

    public:

        struct Mode {
            static const int Read = 0x01, Write = 0x02, Append = 0x04;
        };

};

Is this a good practice?

Answer 1

完全不是，变量是在编译时而不是运行时解析的。