Process V2: Example fails to build when using BOOST_ASIO_SEPARATE_COMPILATION

[reddwarf69]

As can be seen in https://godbolt.org/z/q3r4hjGsd, https://github.com/boostorg/process/blob/develop/example/v2/intro.cpp fails to build when using BOOST_ASIO_SEPARATE_COMPILATION.

(in general, not sure why asio::detail is used to start with)

[klemens-morgenstern]

Did you post the correct godbolt link?

[klemens-morgenstern]

FYI: This is a copy-pasta mistake. process.v2 was originally a PR to go into asio itself.