shared_ptr: add use_count()
shared_ptr: add use_count()

Add a use_count() method for shared_ptr, like std::shared_ptr has.

We already had such a method for lw_shared_ptr, but not for shared_ptr.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@cloudius-systems.com>

koolhazz/seastar,koolhazz/seastar,avikivity/scylla,stamhe/seastar,norcimo5/seastar,senseb/scylla,flashbuckets/seastar,scylladb/seastar,chunshengster/seastar,stamhe/seastar,rluta/scylla,cloudius-systems/seastar,rentongzhang/scylla,dwdm/seastar,dwdm/scylla,asias/scylla,glommer/scylla,wildinto/seastar,leejir/seastar,gwicke/scylla,avikivity/scylla,sjperkins/seastar,stamhe/scylla,shaunstanislaus/scylla,stamhe/scylla,jonathanleang/seastar,cloudius-systems/seastar,jonathanleang/seastar,acbellini/seastar,aruanruan/scylla,duarten/scylla,linearregression/seastar,tempbottle/seastar,kjniemi/seastar,kangkot/scylla,printedheart/seastar,asias/scylla,capturePointer/scylla,acbellini/scylla,phonkee/scylla,senseb/scylla,mixja/seastar,shyamalschandra/seastar,syuu1228/seastar,tempbottle/scylla,linearregression/scylla,eklitzke/scylla,rentongzhang/scylla,aruanruan/scylla,tempbottle/seastar,kjniemi/scylla,kjniemi/scylla,stamhe/seastar,acbellini/seastar,mixja/seastar,dwdm/scylla,anzihenry/seastar,rentongzhang/scylla,scylladb/seastar,bzero/seastar,hongliangzhao/seastar,dwdm/scylla,linearregression/scylla,justintung/scylla,wildinto/scylla,chunshengster/seastar,bzero/seastar,dreamsxin/seastar,bzero/seastar,eklitzke/scylla,scylladb/scylla,xtao/seastar,gwicke/scylla,scylladb/scylla-seastar,hongliangzhao/seastar,flashbuckets/seastar,acbellini/seastar,joerg84/seastar,shyamalschandra/seastar,rluta/scylla,acbellini/scylla,bowlofstew/seastar,linearregression/seastar,respu/scylla,aruanruan/scylla,respu/scylla,scylladb/scylla,koolhazz/seastar,wildinto/seastar,scylladb/scylla-seastar,senseb/scylla,dreamsxin/seastar,joerg84/seastar,phonkee/scylla,duarten/scylla,duarten/scylla,shaunstanislaus/scylla,justintung/scylla,raphaelsc/scylla,victorbriz/scylla,tempbottle/seastar,tempbottle/scylla,capturePointer/scylla,printedheart/seastar,stamhe/scylla,kjniemi/scylla,kangkot/scylla,anzihenry/seastar,shaunstanislaus/scylla,cloudius-systems/seastar,dwdm/seastar,bowlofstew/seastar,wildinto/scylla,wildinto/seastar,respu/scylla,bowlofstew/scylla,avikivity/scylla,kjniemi/seastar,bowlofstew/scylla,avikivity/seastar,glommer/scylla,avikivity/seastar,hongliangzhao/seastar,phonkee/scylla,bowlofstew/scylla,gwicke/scylla,leejir/seastar,norcimo5/seastar,norcimo5/seastar,wildinto/scylla,eklitzke/scylla,printedheart/seastar,linearregression/seastar,anzihenry/seastar,leejir/seastar,guiquanz/scylla,syuu1228/seastar,victorbriz/scylla,dreamsxin/seastar,glommer/scylla,kjniemi/seastar,sjperkins/seastar,bowlofstew/seastar,victorbriz/scylla,scylladb/scylla-seastar,asias/scylla,jonathanleang/seastar,linearregression/scylla,rluta/scylla,justintung/scylla,kangkot/scylla,dwdm/seastar,flashbuckets/seastar,tempbottle/scylla,shyamalschandra/seastar,guiquanz/scylla,syuu1228/seastar,mixja/seastar,scylladb/seastar,xtao/seastar,raphaelsc/scylla,scylladb/scylla,capturePointer/scylla,acbellini/scylla,joerg84/seastar,chunshengster/seastar,sjperkins/seastar,raphaelsc/scylla,xtao/seastar,guiquanz/scylla,scylladb/scylla,avikivity/seastar