Get index in range-based for loop for sequential containers in c++11

Question

I have seen following snippet in Go. Getting index while doing range based for loop.

var pow = []int{1, 2, 4, 8, 16, 32, 64, 128}

for i, v := range pow {
    fmt.Printf("2**%d = %d\n", i, v)
}

Is there any such provision in c++11 in range-based for loop? I know having a variable and incrementing is an option, but this is more powerful.

possible duplicate of [Find position of element in C++11 range-based for loop?](http://stackoverflow.com/questions/10962290/find-position-of-element-in-c11-range-based-for-loop) — awesoon, Sep 06 '15 at 18:54
That, or http://stackoverflow.com/questions/6953128/need-iterator-when-using-ranged-based-for-loops — Brad, Sep 06 '15 at 18:55
no, the question - is there an equivalent in Go to range-for from C++11 . — , Sep 06 '15 at 18:57
You could take a look at range-v3 at github, maybe there will be something interesting. — RippeR, Sep 06 '15 at 22:18

score 0 · Answer 1 · answered Jun 03 '22 at 14:34

Boost has a very nice range adaptor indexed:

  #include <boost/range/adaptors.hpp>
  std::vector<std::string> list = {"boost", "adaptors", "are", "great"};
  for (auto v: list | boost::adaptors::indexed(1)) {
    printf("%ld: %s\n", v.index(), v.value().c_str());
  }

The output:

1: boost
2: adaptors
3: are
4: great

Here we index from 1 (boost::adaptors::indexed(1)), but we could easily index from 0 or any other value also.

Get index in range-based for loop for sequential containers in c++11

1 Answers1