pub fn active_correlation() -> Option<(String, String)>Expand description
Read the active scope’s correlation pair as
Some((trace_id, span_id)) when both have been pushed, otherwise
None. Walks the stack innermost-first so the deepest set value
wins — matches the auto-fill ordering in auto_fill_envelope.
This is the symmetrical read surface to ScopeFrameBuilder (D7-3,
which writes frames). Spec 95 D8-2: outbound HTTP middleware,
OTLP exporters, and any other generic code that needs to inherit
the active trace context calls this function.