Make `pretty` mod or `write_to_ryu_buffer` function public?

[Alexhuszagh]

I already have an intermediate stack buffer, but would like to use the pretty formatting via pretty:{f2s_buffered_n, d2s_buffered_n}. Right now, this is publicly exposed via Float::write_to_ryu_buffer, however, this is very clearly not a public API and likely to change.

Would you be willing to make any guarantees about the write_to_ryu_buffer method in the Float trait, either in the current form, or some new form, or expose the pretty:{f2s_buffered_n, d2s_buffered_n} functions publicly?

[dtolnay]

How's this? #6

[Alexhuszagh]

@dtolnay Excellent, thank you!

[dtolnay]

Okay. :) I published 0.2.7 with those functions exposed. Thanks!