cosmopolitan/ctl/distance.h

// -*-mode:c++;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8-*-
// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
#ifndef CTL_DISTANCE_H_
#define CTL_DISTANCE_H_
#include "iterator.h"
#include "iterator_traits.h"

namespace ctl {

template<class InputIter>
constexpr typename iterator_traits<InputIter>::difference_type
distance_impl(InputIter first, InputIter last, input_iterator_tag)
{
    typename iterator_traits<InputIter>::difference_type res(0);
    for (; first != last; ++first)
        ++res;
    return res;
}

template<class RandIter>
constexpr typename iterator_traits<RandIter>::difference_type
distance_impl(RandIter first, RandIter last, random_access_iterator_tag)
{
    return last - first;
}

template<class InputIter>
constexpr typename iterator_traits<InputIter>::difference_type
distance(InputIter first, InputIter last)
{
    return distance_impl(
      first, last, typename iterator_traits<InputIter>::iterator_category());
}

} // namespace ctl

#endif // CTL_DISTANCE_H_
Introduce more CTL content This change introduces accumulate, addressof, advance, all_of, distance, array, enable_if, allocator_traits, back_inserter, bad_alloc, is_signed, any_of, copy, exception, fill, fill_n, is_same, is_same_v, out_of_range, lexicographical_compare, is_integral, uninitialized_fill_n, is_unsigned, numeric_limits, uninitialized_fill, iterator_traits, move_backward, min, max, iterator_tag, move_iterator, reverse_iterator, uninitialized_move_n This change experiments with rewriting the ctl::vector class to make the CTL design more similar to the STL. So far it has not slowed things down to have 42 #include lines rather than 2, since it's still almost nothing compared to LLVM's code. In fact the closer we can flirt with being just like libcxx, the better chance we might have of discovering exactly what makes it so slow to compile. It would be an enormous discovery if we can find one simple trick to solving the issue there instead. This also fixes a bug in `ctl::string(const string &s)` when `s` is big. 2024-06-28 05:18:55 +00:00			`// --mode:c++;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8--`
			`// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi`
			`#ifndef CTL_DISTANCE_H_`
			`#define CTL_DISTANCE_H_`
			`#include "iterator.h"`
			`#include "iterator_traits.h"`

			`namespace ctl {`

			`template<class InputIter>`
			`constexpr typename iterator_traits<InputIter>::difference_type`
			`distance_impl(InputIter first, InputIter last, input_iterator_tag)`
			`{`
			`typename iterator_traits<InputIter>::difference_type res(0);`
			`for (; first != last; ++first)`
			`++res;`
			`return res;`
			`}`

			`template<class RandIter>`
			`constexpr typename iterator_traits<RandIter>::difference_type`
			`distance_impl(RandIter first, RandIter last, random_access_iterator_tag)`
			`{`
			`return last - first;`
			`}`

			`template<class InputIter>`
			`constexpr typename iterator_traits<InputIter>::difference_type`
			`distance(InputIter first, InputIter last)`
			`{`
			`return distance_impl(`
			`first, last, typename iterator_traits<InputIter>::iterator_category());`
			`}`

			`} // namespace ctl`

			`#endif // CTL_DISTANCE_H_`