optional_chrono_lh
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int>; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 0]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int, std::ratio<1, 1000> >; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 1]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int, std::ratio<1, 1000000> >; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 2]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int, std::ratio<1, 1000000000> >; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 3]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int, std::ratio<1, 1000000000> >; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 4]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = const std::chrono::duration<long int, std::ratio<1, 1000000000> >; long unsigned int <anonymous> = 1; T = struct_with_optional; long unsigned int N = 5]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = long int; long unsigned int <anonymous> = 1; T = struct_with_bogus_duration; long unsigned int N = 0]??? used but never defined
template_constructor_lh
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = short int; long unsigned int <anonymous> = 1; T = aggregate_constrained; long unsigned int N = 0]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = int; long unsigned int <anonymous> = 1; T = aggregate_constrained; long unsigned int N = 1]??? used but never defined
template_forwarding_ref_lh
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = int; long unsigned int <anonymous> = 1; T = aggregate_unconstrained; long unsigned int N = 0]??? used but never defined
../boost/pfr/detail/core14_loophole.hpp:105:15: warning: inline function ???constexpr boost::pfr::detail::loophole_ubiq_lref<T, N>::operator U&() const && [with U = int; long unsigned int <anonymous> = 1; T = aggregate_unconstrained; long unsigned int N = 1]??? used but never defined