Sort the input elements in topological order and write the resulting linear ordered set into the specified resultOutIter. If the sort is unsuccessful (the input is not an acyclic directed graph) write the elements that have not been sorted to the specified unsortedOutIter output. The input elements are provided as a sequence of (conceptual or physical) pairs between the specified relationsBegin and relationsEnd of the form (U, V), where U and V are nodes, and U precedes V in the output. Return true on success, and false if the sort fails due to a cycle in the input. The type bsl::iterator_traits<INPUT_ITER>::value_type must either be bsl or std::pair where the first_type and second_type are the same as bsl::iterator_traits<OUTPUT_ITER>::value_type or TopologicalSortUtilEdgeTraits must be specialized for the type, i.e., the supplied bsl::iterator_traits<INPUT_ITER>::value_type must support the following syntax: ` typedef typename bsl::iterator_traits<INPUT_ITER>::value_type IterValue; typedef typename bsl::iterator_traits<RESULT_ITER>::value_type ResultValue;
Declared in <bdlb_topologicalsortutil.h>
template<
class INPUT_ITER,
class OUTPUT_ITER,
class UNSORTED_OUTPUT_ITER>
static
bool
sort(
INPUT_ITER relationsBegin,
INPUT_ITER relationsEnd,
OUTPUT_ITER resultOutIter,
UNSORTED_OUTPUT_ITER unsortedOutIter);typedef typename TopologicalSortUtilEdgeTraits<IterValue> Traits;
typedef typename Traits::NodeType NodeType;
for (INPUT_ITER it = relationshipPairsBegin; it != relationshipPairsEnd; ++it) {
*result++ = Traits::from(*it); // U *result++ = Traits::to(*it); // V } ` Note that when the method returns false, resultOutIter may contain a subset of the elements in the right topological order, essentially the elements that the routine was able to sort before the cycle was discovered. In that case, the elements that the routine was unable to sort were written to the unsortedOutIter output iterator, in an unspecified order.