fmt 6.0.0 "error C2039: 'back_insert_range': is not a member of 'fmt'" compile error

[lexxmark]

Tried to implement "Custom Formatting of Built-in Types" from documentation
Compile error in the 1st line:
using arg_formatter = fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>>;

[jeanga]

Yeah. It seems the samples from documentation were not updated from 5.X...
We really need some guidance to help upgrade our code to 6.0.

[jeanga]

I found test/std-format-test.cc to be helpful but the docs definitely need some update :*)

[vitaut]

Updated the docs and made buffer_range public in 3f75e2b.