Copyright 2014 The Prometheus Authors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

package prometheus
UntypedOpts is an alias for Opts. See there for doc comments.
type UntypedOpts Opts
UntypedFunc works like GaugeFunc but the collected metric is of type "Untyped". UntypedFunc is useful to mirror an external metric of unknown type. To create UntypedFunc instances, use NewUntypedFunc.
type UntypedFunc interface {
	Metric
	Collector
}
NewUntypedFunc creates a new UntypedFunc based on the provided UntypedOpts. The value reported is determined by calling the given function from within the Write method. Take into account that metric collection may happen concurrently. If that results in concurrent calls to Write, like in the case where an UntypedFunc is directly registered with Prometheus, the provided function must be concurrency-safe.
func ( UntypedOpts,  func() float64) UntypedFunc {
	return newValueFunc(NewDesc(
		BuildFQName(.Namespace, .Subsystem, .Name),
		.Help,
		nil,
		.ConstLabels,
	), UntypedValue, )