<xstd/ints/cstdlib.hpp>

namespace xstd {
  template<integer I>
    struct div_result;
  template<integer I>
    div_result(I, I) -> div_result<I>;

  template<integer I>
    constexpr auto sign(I x) noexcept(nothrow_const_operators<I>) -> int;
  template<integer I>
    constexpr auto abs(I x) noexcept(nothrow_const_operators<I>) -> promoted_t<I>;
  template<integer I>
    constexpr auto unsigned_abs(I x) noexcept(nothrow_const_operators<I>) -> xstd::make_unsigned_t<I>;

  template<integer I>
    constexpr auto div(I numer, I denom) noexcept(nothrow_const_operators<I>) -> div_result<I>;
  template<integer I>
    constexpr auto div_euclid(I numer, I denom) noexcept(nothrow_const_operators<I>) -> div_result<I>;
  template<integer I>
    constexpr auto div_floor(I numer, I denom) noexcept(nothrow_const_operators<I>) -> div_result<I>;
  template<integer I>
    constexpr auto div_ceil(I numer, I denom) noexcept(nothrow_const_operators<I>) -> div_result<I>;
}

Header	Declares
<xstd/ints/cstdlib/div_result.hpp>	div_result
<xstd/ints/cstdlib/sign.hpp>	sign
<xstd/ints/cstdlib/abs.hpp>	abs
<xstd/ints/cstdlib/unsigned_abs.hpp>	unsigned_abs
<xstd/ints/cstdlib/div.hpp>	div
<xstd/ints/cstdlib/div_euclid.hpp>	div_euclid
<xstd/ints/cstdlib/div_floor.hpp>	div_floor
<xstd/ints/cstdlib/div_ceil.hpp>	div_ceil

xstd::make_unsigned_t and xstd::numeric_limits below are xstd's, which extend the standard's to every integer.

The umbrella exports each header below.

Each function is constrained on integer, so a character type and bool, which are integral, are turned away.

Each division header exports div_result with it.

The four divisions take their result vocabulary and their rounding semantics from P3724R4, and only these four of its rounding modes.