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Obtaining a function pointer from an iterator over a function deque

开发者 https://www.devze.com 2023-01-25 01:02 出处:网络
I\'m trying to build a simple deficit round robin scheduler, and right now I\'m trying to get the function that has had the least time running. I\'m getting a \"Bus Error\" returned to me when I try t

I'm trying to build a simple deficit round robin scheduler, and right now I'm trying to get the function that has had the least time running. I'm getting a "Bus Error" returned to me when I try to convert an iterator to a pointer. Below is my code, ptof is simply a typedef pointer to the kind of functions I have in my deque and State has the info for each process. What am I doing wrong? Your help would be greatly appreciated.

ptof leastTime(deque<ptof> fnc, map<ptof, State *> s){
double leastElapsed= 100000000;
ptof  f;

deque<ptof>::iterator it;
for (it=fnc.begin() ; it < fnc.end(); it++ ){
if(s[*it]->elapsed<leastElapsed){
     f = (ptof)(&(*it)); 
cout<< s[f]->name<&l开发者_StackOverflowt;endl;
     }
  }
return f;
}


f = (ptof)(&(*it)); 

That would be taking the address of the function pointer. Try

f = *it;

In any case, avoid C-style casts. If you tried a static_cast instead, the compiler would tell you that the cast is invalid.


Taking the address of what the iterator points to is rather odd too, it looks like you're casting a pointer to a function pointer to a function pointer, which isn't what you wanted I don't think.

The c-style cast doesn't help because it could be doing any kind of cast, even one you didn't want.

For something like this in C++ it might be cleaner to define an interface with a virtual function to avoid the mess that can be function pointers.

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