20 General utilities library [utilities]

20.2 Utility components [utility]

20.2.7 Integer comparison functions [utility.intcmp]

template<class T, class U> constexpr bool cmp_equal(T t, U u) noexcept;
Mandates: Both T and U are standard integer types or extended integer types ([basic.fundamental]).
Effects: Equivalent to:
using UT = make_unsigned_t<T>;
using UU = make_unsigned_t<U>;
if constexpr (is_signed_v<T> == is_signed_v<U>)
  return t == u;
else if constexpr (is_signed_v<T>)
  return t < 0 ? false : UT(t) == u;
else
  return u < 0 ? false : t == UU(u);
template<class T, class U> constexpr bool cmp_not_equal(T t, U u) noexcept;
Effects: Equivalent to: return !cmp_­equal(t, u);
template<class T, class U> constexpr bool cmp_less(T t, U u) noexcept;
Mandates: Both T and U are standard integer types or extended integer types ([basic.fundamental]).
Effects: Equivalent to:
using UT = make_unsigned_t<T>;
using UU = make_unsigned_t<U>;
if constexpr (is_signed_v<T> == is_signed_v<U>)
  return t < u;
else if constexpr (is_signed_v<T>)
  return t < 0 ? true : UT(t) < u;
else
  return u < 0 ? false : t < UU(u);
template<class T, class U> constexpr bool cmp_greater(T t, U u) noexcept;
Effects: Equivalent to: return cmp_­less(u, t);
template<class T, class U> constexpr bool cmp_less_equal(T t, U u) noexcept;
Effects: Equivalent to: return !cmp_­greater(t, u);
template<class T, class U> constexpr bool cmp_greater_equal(T t, U u) noexcept;
Effects: Equivalent to: return !cmp_­less(t, u);
template<class R, class T> constexpr bool in_range(T t) noexcept;
Mandates: Both T and R are standard integer types or extended integer types ([basic.fundamental]).
Effects: Equivalent to:
return cmp_greater_equal(t, numeric_limits<R>::min()) &&
       cmp_less_equal(t, numeric_limits<R>::max());
[Note:
These function templates cannot be used to compare byte, char, char8_­t, char16_­t, char32_­t, wchar_­t, and bool.
— end note]