大型项目的C ++异常

Question

I'm currently building a C++ game engine as a learning exercise, and am incorporating exceptions into the less performance-critical sections. I'm primarily a PHP and Ruby developer, so I'm used to declaring new classes of exception on a regular basis using simple syntax like this:

class SomeSubSystemException < Exception; end

or

class SomeSubSystemException extends Exception {};

is there an easy syntax for doing this in C++, or am I going about exception handling the wrong way for C++ projects? Currently I have to do the following for every class of exception, which makes me want to not define very many:

class SubSystemException : public MainException {
    SubSystemException(std::string& msg) : MainException(msg) {}
};

Thanks in advance!

Answer 1

Define a Macro that does that for you.

#define NEW_EXC(Derived, Base) class Derived : Base {\
 Derived(const std::string& msg) : Base(msg) {}

NEW_EXC(SubSystemException, MainException);

#undef NEW_EXC

Done.

Beware macros can be evil.

Answer 2

Although I agree with the comment from Bo Person saying that this will not be your main source of boilaerplate, here another way for the heck of it:

Use CRTP

template<class T>
class MainException : public std::runtime_error{
private:
  MainException(std::string const& msg):std::runtime_error(msg){ }
public:
  static MainException<T> create(std::string const& msg){
    return MainException<T>(msg);
  }
};

//Usage:
class MyException : public MainException<MyException> {};
void foo(){
  MyException::create(std::string("Foo"));
}