如何理解我在源代码中找到的这个C ++类声明？

Question

I'm going through a piece of C++ source code for a personal project I'm working on and I can't for the world figure out what's happening in the following snippet:

Event EV_ScriptThread_Execute(
    "execute", EV_DEFAULT, NULL, NULL, "Execute the thread."
);

class ScriptThread : Listener
{
    { &EV_ScriptThread_Execute, Execute },
    { NULL, NULL}
};

void ScriptThread::Execute(Event *ev)    
{
    //Stuff
}

As far as I can interpret, it creates an instance of the Event-class and stores it in EV_ScriptThread_Execute . It then defines the ScriptThread-class, but I have no idea how to interpret the line after it.

Could someone explain me what happens? How would { &EV_ScriptThread_Execute, Execute }, look like if it was written in full, and not, as it seems, a short-hand notation.

EDIT: Apparantly I misintepreted the macro-definition which I thought would produce: class ScriptThread : Listener , based on all the replies I went back and found out it actually construct an array of some sort. It still kind of leaves me in the dark on what happens... as I can't actually compile the code (since it's just a snippet), I can't really look at the precompiled files either.

What is the result of this?

ResponseDef<ScriptThread> ScriptThread::Responses[] =
{
    { &EV_ScriptThread_Execute, Execute },
    { NULL, NULL}
};

Another EDIT: So I found ResponseDef is a struct which looks like this:

template< class Type >
struct ResponseDef
{
    Event *event;
    void (Type::*response)(Event *event);
};

Conclusively this means the array gets filled up with a structure which takes both a pointer to an instance of Event as well as a pointer to a method, which would explain the initializer!

Thanks to everyone for brining me back on track!

Answer 1

Look for a macro definition for Listener. I'm pretty sure that something horrible is hiding behind that. There is no other way to turn this snippet into something a C++ compiler will accept.

I expect something like:

#define Listener ScriptBaseClass { void Execute(Event *ev); } the_script[] =

Answer 2

Searching for the longest single token, EV_ScriptThread_Execute , turns up this:

Event EV_ScriptDoor_DoInit( "doinit" );   
Event EV_ScriptDoor_SetOpenThread( "openthread" );   
Event EV_ScriptDoor_SetCloseThread( "closethread" );   

ResponseDef ScriptDoor::Responses[] =   
{   
    { &EV_ScriptDoor_DoInit,           ( Response )ScriptDoor::DoInit },   
    { &EV_Door_DoClose,                  ( Response )ScriptDoor::DoClose },   
    { &EV_Door_DoOpen,                   ( Response )ScriptDoor::DoOpen },   
    { &EV_ScriptDoor_SetOpenThread,           ( Response )ScriptDoor::SetOpenThread },   
    { &EV_ScriptDoor_SetCloseThread,          ( Response )ScriptDoor::SetCloseThread },   
    { NULL, NULL }   
};

From here: .htm">http://read.pudn.com/downloads99/sourcecode/windows/bitmap/406853/doors.cpp_.htm

It's clearly related code, and what is it from? Quake 2. So that's what we're looking at--for anything more detailed about how or why your specific bit of code works, we'd need to see (or find) more...and that may be a bit tricky given the revision history listed in the above file:

// 48    8/24/98 11:32a Markd   
// Added Start method to threads, repladed all ProcessEvent(   
// EV_ScriptThread_execute) with thread->Start( -1 )   

Maybe someone else knows who Markd is; I don't.