How to use range-v3's ranges::actions::transform?

Question

I want to use ranges-v3 to transform an array in place. I can use ranges::transform successfully, but failed to use actions::transform.

int arr[]{1, 2, 3};
auto fn = [](auto e) { return e + 1; };
ranges::transform(arr, std::begin(arr), fn); // ok
arr |= actions::transform(std::begin(arr), fn); // error

Error Message:

fatal error: no matching function for call to object of type 'const ranges::actions::transform_fn'
        arg |= actions::transform(std::begin(arr), std::begin(arr),
               ^~~~~~~~~~~~~~~~~~

How to use actions::transform in such a case?

Your error message doesn't seem to correspond to the line of code. — cigien, Apr 13 '20 at 13:29
Yes, but the error message text doesn't seem to match up to that line. — cigien, Apr 13 '20 at 13:33

cigien · Answer 1 · 2020-04-13T13:33:03.393

2

In range-v3, you would simply do

arr |= ranges::actions::transform(fn);

Here's a demo

edited Apr 13 '20 at 13:33

answered Apr 13 '20 at 13:27

cigien

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How to use range-v3's ranges::actions::transform?

1 Answers1