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Showing content from https://en.cppreference.com/w/cpp/language/../keyword/../algorithm/ranges/sort_heap.html below:

std::ranges::sort_heap - cppreference.com

Call signature

Sorts the elements in the specified range with respect to comp and proj, where the range originally represents a heap with respect to comp and proj. The sorted range no longer maintains the heap property.

1) The specified range is [first, last).

2) The specified range is r.

If the specified range is not a heap with respect to comp and proj, the behavior is undefined.

The function-like entities described on this page are algorithm function objects (informally known as niebloids), that is:

• Explicit template argument lists cannot be specified when calling any of them.
• None of them are visible to argument-dependent lookup.
• When any of them are found by normal unqualified lookup as the name to the left of the function-call operator, argument-dependent lookup is inhibited.

1) last

At most \(\scriptsize 2N \cdot \log(N)\)2N⋅log(N) applications of comp and \(\scriptsize 4N \cdot \log(N)\)4N⋅log(N) applications of proj, where \(\scriptsize N \)N is:

struct sort_heap_fn
{
    template<std::random_access_iterator I, std::sentinel_for<I> S,
             class Comp = ranges::less, class Proj = std::identity>
        requires std::sortable<I, Comp, Proj>
    constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
    {
        auto ret{ranges::next(first, last)};
        for (auto last{ret}; first != last; --last)
            ranges::pop_heap(first, last, comp, proj);
        return ret;
    }
 
    template<ranges::random_access_range R,
             class Comp = ranges::less, class Proj = std::identity>
        requires std::sortable<ranges::iterator_t<R>, Comp, Proj>
    constexpr ranges::borrowed_iterator_t<R>
        operator()(R&& r, Comp comp = {}, Proj proj = {}) const
    {
        return (*this)(ranges::begin(r), ranges::end(r), std::move(comp), std::move(proj));
    }
};
 
inline constexpr sort_heap_fn sort_heap{};

#include <algorithm>
#include <array>
#include <iostream>
 
void print(auto const& rem, const auto& v)
{
    std::cout << rem;
    for (const auto i : v)
        std::cout << i << ' ';
    std::cout << '\n';
}
 
int main()
{
    std::array v{3, 1, 4, 1, 5, 9};
    print("original array:  ", v);
 
    std::ranges::make_heap(v);
    print("after make_heap: ", v);
 
    std::ranges::sort_heap(v);
    print("after sort_heap: ", v);
}

Output:

original array:  3 1 4 1 5 9
after make_heap: 9 5 4 1 1 3
after sort_heap: 1 1 3 4 5 9

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