Struct MetricEncoder 

pub struct MetricEncoder { /* private fields */ }

A writer that deduplicates HELP and TYPE metadata lines during Prometheus encoding.

When the same metric is registered multiple times with different attribute values (via sub_registry_with_label), prometheus_client outputs duplicate HELP/TYPE lines. This writer filters them in a single pass to produce canonical Prometheus format.

Uses “first wins” semantics: keeps the first HELP/TYPE description encountered for each metric name and discards subsequent duplicates.

Implementations

impl MetricEncoder

pub fn new() -> Self

pub fn into_string(self) -> String

Trait Implementations

impl Default for MetricEncoder

fn default() -> Self

Returns the “default value” for a type.

impl Write for MetricEncoder

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.