using System;

using System.Collections.Generic;

using System.Diagnostics;

​

public static class DictionaryExtensions

{

    public static bool TryAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue value)

    {

        if (dictionary == null)

        {

            throw new ArgumentNullException(nameof(dictionary));

        }

​

        if (!dictionary.ContainsKey(key))

        {

            dictionary.Add(key, value);

            return true;

        }

​

        return false;

    }   

    public static bool TryAddViaException<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue value)

    {

        if (dictionary == null)

        {

            throw new ArgumentNullException(nameof(dictionary));

        }

        try

        {

            dictionary.Add(key, value);

            return true;

        }

        catch (ArgumentException)

        {

            return false;

        }

    }

}

​

static class Program

{

    public static void Main()

    {

        Measure((d, k, v) => d.TryAdd(k, v), "TryAdd");

        GC.Collect();

        Measure((d, k, v) => d.TryAddViaException(k, v), "TryAddViaException");

    }

    private static void Measure(Func<IDictionary<string, int>, string, int, bool> f, string name)

    {

        var dictionary = new Dictionary<string, int>();

        for (var i = 0; i < 50_000; i += 1)

        {

            dictionary.Add(i.ToString(), i);

        }

        var stopwatch = new Stopwatch();

        stopwatch.Start();

        for (var i = 25_000; i < 75_000; i += 1)

        {

            f(dictionary, i.ToString(), i);

        }

        stopwatch.Stop();

        Console.WriteLine($"{name}: {stopwatch.Elapsed}");

    }

}