C ++宏定义不清楚

Question

Is this a macro defintion for a class or what exactly is it?

#define EXCEPTIONCLASS_IMPLEMENTATION(name, base, string) : public base     \
    {                                                               \
public:                                                                 \
    name() : base(string) {}                                            \
    name(const x::wrap_exc& next) : base(string,next) {};               \
    name(const x::wrap_exc& prev, const x::wrap_exc& next) :            \
        base(prev, next) {};                                            \
}

Answer 1

It is a macro definition for an exception class.

It looks somebody wants you to write code like this:

class my_exception EXCEPTIONCLASS_IMPLEMENTATION(my_exception, std::exception, "What a mess!")

The pre-processor will spit out:

class my_exception : public std::exception { public: my_exception() : std::exception("What a mess!") {} my_exception(const x::wrap_exc& next) : std::exception("What a mess!",next) {}; my_exception(const x::wrap_exc& prev, const x::wrap_exc& next) : std::exception(prev, next) {}; }

What exactly is it?

It is an abomination!

Answer 2

它是异常的宏，用标准构造函数创建异常。