Revisit Try Catch Overhead

During a lunch break, a colleague said there is no try-catch overhead in C# if there is no exception thrown, this surprised me. From what I understand in C++, overhead is always there for try-catch setup, even though no exception is thrown, the language does not know if it will throw. Let's do a weekend small project to find this out with a nice bench mark library [benchmarkdotnet](https://benchmarkdotnet.org/articles/guides/getting-started.html "benchmarkdotnet")

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

var summary = BenchmarkRunner.Run<TryCatchOverHead>();

public class TryCatchOverHead
{

    [Benchmark]
    public int NotTryCatch()
    {
        var a = 1;
        var b = 2;
        var result = a / b;
        return result;
    }

    [Benchmark]
    public int NotExceptionThrow()
    {
        try
        {
            var a = 1;
            var b = 2;
            var result = a / b;
            return result;
        }
        catch (Exception ex)
        {
            return 0;
        }
    }

    [Benchmark]
    public int ExceptionThrow()
    {
        try
        {
            var a = 1;
            var b = 0;
            var result = a / b;
            return result;
        }
        catch (Exception ex)
        {
            return 0;
        }
    }
}

The output, No try-catch is about 20 times faster than try catch block, with 0.014ns vs 0.274ns

Does it matter? As an engineer, we should know the purpose of try-catch. It is used to deal with exceptions and continue the work, not fatal handling without a reason.

// * Summary *

BenchmarkDotNet v0.13.6, Windows 10 (10.0.19045.3208/22H2/2022Update)
Intel Core i5-4590 CPU 3.30GHz (Haswell), 1 CPU, 4 logical and 4 physical cores
.NET SDK 7.0.100
  [Host]     : .NET 7.0.0 (7.0.22.51805), X64 RyuJIT AVX2
  DefaultJob : .NET 7.0.0 (7.0.22.51805), X64 RyuJIT AVX2

|            Method |          Mean |      Error |     StdDev |
|------------------ |--------------:|-----------:|-----------:|
|       NotTryCatch |     0.0141 ns |  0.0130 ns |  0.0121 ns |
| NotExceptionThrow |     0.2744 ns |  0.0063 ns |  0.0053 ns |
|    ExceptionThrow | 7,624.9444 ns | 66.1726 ns | 58.6603 ns |

// * Warnings *
ZeroMeasurement
  TryCatchOverHead.NotTryCatch: Default -> The method duration is indistinguishable from the empty method duration

// * Hints *
Outliers
  TryCatchOverHead.NotExceptionThrow: Default -> 2 outliers were removed (2.15 ns, 2.15 ns)
  TryCatchOverHead.ExceptionThrow: Default    -> 1 outlier  was  removed (7.82 us)

// * Legends *
  Mean   : Arithmetic mean of all measurements
  Error  : Half of 99.9% confidence interval
  StdDev : Standard deviation of all measurements
  1 ns   : 1 Nanosecond (0.000000001 sec)

// ***** BenchmarkRunner: End *****
Run time: 00:01:00 (60.65 sec), executed benchmarks: 3

Global total time: 00:01:05 (65.36 sec), executed benchmarks: 3
// * Artifacts cleanup *
Artifacts cleanup is finished