std::for_each with C-style arrays

Although std::for_each is most often used with the standard containers, it can also be used with C-style arrays. Take for example the following:

#include <algorithm>
#include <functional>
// ...
WriterTask writer[NumThreads];
std::for_each(writer, writer+NumThreads, 
   std::mem_fun_ref(&WriterTask::activate));
// ...
std::for_each(writer, writer+NumThreads, 
   std::mem_fun_ref(&WriterTask::join));

Or if you prefer:

std::for_each(&writer[0], &writer[NumThreads],
   std::mem_fun_ref(&WriterTask::activate));

Compare the above with the explicit for loop:

for (int i = 0; i < NumThreads; ++i) {
   writer[i].activate();
}

I'm not completely convinced that the std::for_each case is more readable. However, I liked it better than the for loop for some test cases I was writing. It collapsed a number of subsequent for loops down into one line statements making it clearer the intent of the test.