id summary reporter owner description type status milestone component version severity resolution keywords cc 11379 pairing_heap::end requires compare functor to be default constructible anonymous timblechmann 'boost::heap::pairing_heap >::end' tries to default-construct a 'Compare' object, and fails to compile if 'Compare' is not default constructible. This is an error. If the iterator requires a 'Compare' object, it should copy-construct this from the object stored in the heap data structure. See attached file for a minimal example Bugs closed To Be Determined heap Boost 1.58.0 Problem fixed