avoid building temporary shared_ptrs in UTreeEvaluator
avoid building temporary shared_ptrs in UTreeEvaluator

agra-uni-bremen/metaSMT,nbruns1/metaSMT,hoangmle/metaSMT,agra-uni-bremen/metaSMT,finnhaedicke/metaSMT,hoangmle/metaSMT,finnhaedicke/metaSMT,hoangmle/metaSMT,nbruns1/metaSMT,finnhaedicke/metaSMT,agra-uni-bremen/metaSMT,nbruns1/metaSMT