../units/src/core/include/units/magnitude.h: In instantiation of 'static constexpr intmax_t units::detail::prime_factorization<N>::get_or_compute_first_factor() [with long long int N = 149597870700; intmax_t = long long int]':
../units/src/core/include/units/magnitude.h:627:74: required from 'constexpr const intmax_t units::detail::prime_factorization<149597870700>::first_base'
../units/src/core/include/units/magnitude.h:632:54: required from 'constexpr const auto units::detail::prime_factorization<149597870700>::value'
../units/src/core/include/units/magnitude.h:631:25: required from 'struct units::detail::prime_factorization<149597870700>'
../units/src/core/include/units/magnitude.h:642:71: required from 'constexpr const auto units::detail::prime_factorization_v<149597870700>'
../units/src/core/include/units/magnitude.h:655:18: required from 'constexpr auto [requires units::Magnitude<<placeholder>, >] units::mag() [with ratio R = ratio{149597870700, 1}]'
../units/src/systems/si/include/units/isq/si/length.h:59:91: required from here
../units/src/core/include/units/magnitude.h:623:70: error: unsigned conversion from 'long long int' to 'std::size_t' {aka 'unsigned int'} changes value from '149597870700' to '3568982636' [-Werror=overflow]
623 | return static_cast<std::intmax_t>(factorizer::find_first_factor(N));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
This lets us remove a ton of special-casing throughout the codebase, and
just generally makes things a lot simpler.
We also remove the ability to take rational powers of `ratio`, including
`sqrt` and `cbrt` helpers, because these are intrinsically ill-defined.
Fixes#369.
The algorithm is exactly the same; we just get our values for
`num_value`, `den_value`, and `exp10` in different ways.
The old printing logic assumed the ratio/Magnitude was an exact rational
number. Formerly, we couldn't even _represent_ anything else, but with
Magnitude, we can. Thus, we guard this assumption with a
`static_assert`. Later on, we can figure out how we want to print
irrational bases and/or rational powers. The point of this change is to
unblock us from moving to the new infrastructure.
Björn Schäpers
Mateusz Pusz
Johel Ernesto Guerrero Peña
Chip Hogg