sstring: add conversion from std::string
sstring: add conversion from std::string

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