Error in is_heap_tests.hpp

[cogle]

Currently in is_heap_tests.hpp lines 359-361 will not compile or will eventually not compile for any user using C++ 17.

The specific code causing this issue are the following lines

test_is_heap(execution::seq, IteratorTag(), test_for_is_heap);
test_is_heap(execution::par, IteratorTag(), test_for_is_heap);
test_is_heap(execution::par_unseq, IteratorTag(), test_for_is_heap);

These lines match to a templated function with the following signature

template <typename ExPolicy, typename IteratorTag, typename DataType = int>
void test_is_heap(ExPolicy policy, IteratorTag, DataType = DataType(),
    bool test_for_is_heap = true)

This is a subtle bug but the DataType is now a bool due to test_for_is_heap being a bool; this becomes an issue because in test_is_heap the following attempts to instantiate an vector of numbers beginning from a random point.

std::vector<DataType> c(10007);
std::iota(std::begin(c), std::end(c), DataType(std::rand()));

This was not a problem before because the pre-increment operator was implemented for type bool; with C++ 17 this is no longer the case and this operator has been deprecated. Therefor any C++ 17 compliant compiler will fail to compile at this point ++operator source. In addition the test most likely intended to test whether with the int data type.

[hkaiser]

@cogle Thanks for reporting this issue.