const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);