Compliation error fix.
Compliation error fix.

ersanliqiao/mlpack,bmswgnp/mlpack,chenmoshushi/mlpack,ersanliqiao/mlpack,thirdwing/mlpack,BookChan/mlpack,ranjan1990/mlpack,darcyliu/mlpack,darcyliu/mlpack,palashahuja/mlpack,bmswgnp/mlpack,palashahuja/mlpack,chenmoshushi/mlpack,trungda/mlpack,Azizou/mlpack,Azizou/mlpack,datachand/mlpack,stereomatchingkiss/mlpack,stereomatchingkiss/mlpack,ranjan1990/mlpack,ajjl/mlpack,Azizou/mlpack,erubboli/mlpack,BookChan/mlpack,minhpqn/mlpack,erubboli/mlpack,ajjl/mlpack,minhpqn/mlpack,theranger/mlpack,palashahuja/mlpack,datachand/mlpack,theranger/mlpack,minhpqn/mlpack,chenmoshushi/mlpack,ranjan1990/mlpack,trungda/mlpack,lezorich/mlpack,BookChan/mlpack,trungda/mlpack,lezorich/mlpack,thirdwing/mlpack,bmswgnp/mlpack,ajjl/mlpack,thirdwing/mlpack,ersanliqiao/mlpack,darcyliu/mlpack,lezorich/mlpack,datachand/mlpack,stereomatchingkiss/mlpack,theranger/mlpack,erubboli/mlpack