shuffle_random removed in C++17 on FreeBSD/Clang??

shuffle_random removed in C++17 on FreeBSD/Clang??

[Willem Jan Withagen]

Hi,

As a consequence of the move to C++17 I'm running into this problem.

--WjW

I'm getting this error:
/home/jenkins/workspace/ceph-master/src/osd/ReplicatedBackend.cc:1369:8: 
error: no member named 'random_shuffle' in namespace 'std'
   std::random_shuffle(shuffle.begin(), shuffle.end());
   ~~~~~^
1 error generated.

And the includefile tells me:
template <class RandomAccessIterator>
     void
     random_shuffle(RandomAccessIterator first, RandomAccessIterator 
last); // deprecated in C++14, removed in C++17

Re: shuffle_random removed in C++17 on FreeBSD/Clang??

[Gregory Farnum]

On Tue, Jan 9, 2018 at 2:10 AM, Willem Jan Withagen <wjw@digiware.nl> wrote:
> Hi,
>
> As a consequence of the move to C++17 I'm running into this problem.
>
> --WjW
>
> I'm getting this error:
> /home/jenkins/workspace/ceph-master/src/osd/ReplicatedBackend.cc:1369:8:
> error: no member named 'random_shuffle' in namespace 'std'
>   std::random_shuffle(shuffle.begin(), shuffle.end());
>   ~~~~~^
> 1 error generated.
>
> And the includefile tells me:
> template <class RandomAccessIterator>
>     void
>     random_shuffle(RandomAccessIterator first, RandomAccessIterator last);
> // deprecated in C++14, removed in C++17

Hmm, yep! http://en.cppreference.com/w/cpp/algorithm/random_shuffle

Looks like we're just using it to re-order the list and pick a random
source, so it should be easy enough to replace with a range-restricted
integer selection. Here's a quick hack of a fix:
https://github.com/ceph/ceph/pull/19873
-Greg

Re: shuffle_random removed in C++17 on FreeBSD/Clang??

[Jesse Williamson]

On Tue, 9 Jan 2018, Willem Jan Withagen wrote:

Hi Willem,

> As a consequence of the move to C++17 I'm running into this problem.

std::random_shuffle() was deprecated in C++14 and removed in C++17. Use 
std::shuffle().

The process is:

0) make a random device (ie. std::random_device)
1) make a distribution associated with that device (ie. std::mt19937)
2) shuffle!

I hope that helps,

-Jesse

Re: shuffle_random removed in C++17 on FreeBSD/Clang??

[Willem Jan Withagen]

On 09/01/2018 22:22, Jesse Williamson wrote:
> On Tue, 9 Jan 2018, Willem Jan Withagen wrote:
> 
> Hi Willem,
> 
>> As a consequence of the move to C++17 I'm running into this problem.
> 
> std::random_shuffle() was deprecated in C++14 and removed in C++17. Use 
> std::shuffle().
> 
> The process is:
> 
> 0) make a random device (ie. std::random_device)
> 1) make a distribution associated with that device (ie. std::mt19937)
> 2) shuffle!

Yup,
That was what I found as well.
PR was submitted.

--WjW