Trait MetricsState 

pub trait MetricsState: 'static + Sealed {
    type Handle;
}

Typestate marker for whether a Context tracks runtime metrics.

This trait is sealed and is implemented for exactly two types:

• DfirMetrics: metrics are tracked. The context holds a shared Rc<DfirMetrics> handle which is updated by the generated code and exposed via Dfir::metrics.
• (): metrics are not tracked. The handle is the zero-sized (), so the context statically contains no metrics state at all, and the metrics() accessors do not exist.

Which one is used is determined at codegen time by AsCodeOptions::include_metrics_tracking, so there is no runtime check or default-allocated metrics when tracking is disabled.

Required Associated Types

type Handle

The metrics handle stored inside the context: Rc<DfirMetrics> or ().

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl MetricsState for ()

Metrics are not tracked. Zero-sized, no runtime cost.

type Handle = ()

Implementors

impl MetricsState for DfirMetrics

Metrics are tracked.

type Handle = Rc<DfirMetrics>