5 Quantities and units library [quantities]

5.6 Quantity [qty]

5.6.4 Static member functions [qty.static]

static constexpr quantity zero() noexcept
  requires see below;
static constexpr quantity one() noexcept
  requires see below;
static constexpr quantity min() noexcept
  requires see below;
static constexpr quantity max() noexcept
  requires see below;

Let F be one of zero, one, min, and max.

Returns: {representation_values<rep>::F(), R}.

Remarks: The expression in the requires-clause is equivalent to: requires { representation_values<rep>::F(); }