string::resize_and_overwrite

[vinniefalco]

We should add string::resize_and_overwrite as per P1072R10 (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1072r10.html). The function serialize_impl can be changed to use it.

[vinniefalco]

I guess we would want to deprecate string::grow

[grisumbras]

You mean, alternative implementation when C++23 is supported?

[vinniefalco]

add it to json::string

[grisumbras]

But how would serialize_impl use it? It doesn't use json::string.

[vinniefalco]

I thought there was an overload the serialized to json::string?

[grisumbras]

This doesn't seem to be the case.

[vinniefalco]

We could add it. Anyway json::string::resize_and_overwrite is a better API than the current json::string::grow