prometheus::register_histogram

macro_rules! register_histogram {
    ( $ NAME : expr , $ HELP : expr ) => { ... };
    ( $ NAME : expr , $ HELP : expr , $ CONST_LABELS : expr ) => { ... };
    ( $ NAME : expr , $ HELP : expr , $ CONST_LABELS : expr , [ $ ( $ BUCKETS : expr ) , + ] ) => { ... };
    ( $ OPTS : expr ) => { ... };
}

Create a Histogram and register to default registry.

Examples

let opts = histogram_opts!("test_macro_histogram",
                            "help",
                            labels!{"test" => "hello", "foo" => "bar",});

let res1 = register_histogram!(opts);
assert!(res1.is_ok());

let res2 = register_histogram!("test_macro_histogram_2", "help");
assert!(res2.is_ok());

let res3 = register_histogram!("test_macro_histogram_3", "help", labels!{"a" => "b",});
assert!(res3.is_ok());

let res4 = register_histogram!("test_macro_histogram_4",
                                "help",
                                labels!{"a" => "b",},
                                [Vec::from(&[1.0, 2.0] as &[f64])]);
assert!(res4.is_ok());