<PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.1" />

MeasurementCallback<T>

public sealed delegate MeasurementCallback<T> : MulticastDelegate where T : struct
A delegate to represent the Meterlistener callbacks that are used when recording measurements.
using System.Collections.Generic; using System.Runtime.CompilerServices; namespace System.Diagnostics.Metrics { public delegate void MeasurementCallback<T> ([System.Runtime.CompilerServices.Nullable(1)] Instrument instrument, T measurement, [System.Runtime.CompilerServices.Nullable(new byte[] { 0, 0, 1, 2 })] ReadOnlySpan<KeyValuePair<string, object>> tags, [System.Runtime.CompilerServices.Nullable(2)] object state) where T : struct; }