From: Michael R. Crusoe <michael.crusoe@gmail.com>
Subject: Make explicit cast to bool
--- a/assembler/src/common/func/pred.hpp
+++ b/assembler/src/common/func/pred.hpp
@@ -33,7 +33,7 @@
                 : data_(std::move(p)) { }
 
         virtual bool operator()(T x) const override {
-            return data_(x);
+            return (bool) data_(x);
         }
 
         P data_;
