Can _Cilk_for iterate on STL maps?

[Jorge_Martinis]

Hi!

I have this loop iterating over a std::map:

for(std::map::const_iterator it = MyMap.begin(); it != MyMap.end(); it++)

No insertions/deletions are performer within the loop. Instead, values are just read from the tree as it is traversed.

1) Is random-access to elements and loop count computation at constant time mandatory?

2) Is it safe to use _Cilk_for on this loop?

Thanks!

[Brandon_H_Intel]

Hi Jorge,

This kind of loop won't work with a cilk_for. You'll get the following compiler error:

[plain] error: no operator "-" matches these operands[/plain]

This is because cilk_for needs to be able to randomly access the container elements so it can dynamically split ranges in half as it spawns out work to be done in parallel.