Found the following significant warnings:
  regression_metrics.cpp:47:36: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:47:53: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:52:40: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:52:57: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:62:42: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:62:59: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:67:49: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:67:66: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:72:41: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:72:58: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:77:48: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:77:65: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:82:41: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:82:58: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:87:52: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:87:69: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:92:45: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:92:62: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:97:48: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:97:65: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:102:50: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:102:67: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:107:57: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
  regression_metrics.cpp:107:74: warning: explicitly assigning value of variable of type 'Rcpp::NumericVector' (aka 'Vector<14>') to itself [-Wself-assign-overloaded]
See ‘/Volumes/SSD-Data/Builds/R-dev-web/QA/Simon/packages/el-capitan-x86_64/results/3.6/scorer.Rcheck/00install.out’ for details.