NetAllocs.cs

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Engines;
using BenchmarkDotNet.Running;
using System.Text;

BenchmarkRunner.Run<Benchmarks>();

[MemoryDiagnoser]
public class Benchmarks
{
    private byte[] data;
    private Consumer consumer;

    public Benchmarks()
    {
        data = new byte[128];
        consumer = new Consumer();
    }

    [Benchmark]
    public StringBuilder A() => new StringBuilder();

    [Benchmark]
    public (int, (int, (int, int, int)), string) B() => (1, (1, (1, 1, 1)), "x");

    [Benchmark]
    public void C() => data.Where(x => x > 0).Select(x => x * x).Consume(consumer);

    [Benchmark]
    public string D() => new string('x', 64);
}

internal class DataClass
{
}