Hi,
recently I noticed that removing accidentally included <chrono> in common
header reduced compile time by 10%. I know about tools like IWYU, but
a) they dont always work
b) in cases when I need something simple from a header(e.g. chrono
nanoseconds or unique_ptr I have to include entire chrono/memory)

Are there any proposals that might make this easier to manage?
Either more granular headers like <smart_ptr> <chrono_types> or something
with fwd declarations maybe(although not sure if that would help with
template heavy code like std:: implementations)

P.S. this is nothing against chrono, it's C++20 additions are amazing, but
they just seem to kill compile times.