What is the purpose of opentelemetry::global::set_text_map_propagator

[gliderkite]

What is thew purpose of opentelemetry::global::set_text_map_propagator?

I can't find any exhausting documentation about it, and I was able to setup traces propagation between multiple services (following this answer) without the need to set any TextMapPropagator.

[jtescher]

The propagation API spec should have the clearest answers for the purpose and requirements. Here's the specific requirement for setting a global propagator https://github.com/open-telemetry/opentelemetry-specification/blob/v1.22.0/specification/context/api-propagators.md#set-global-propagator

[gliderkite]

Perfect, thanks!
I link to those docs in the Rust API docs would be useful, if not having a summary directly in there.