Macro counter

macro_rules! counter {
    ($metric:ident $(. $suffixes:ident)*  = $metric_value:expr $(, $attrs:ident=$values:expr)*) => { ... };
}

Records an increment to the named counter with the given attributes.

The increment may only be an i64 or f64. You must not mix types for the same metric.

counter!(spin.metric_name = 1, metric_attribute = "value");