Type extension methods

[AlexRadch]

Add type extension methods.

public static class ThrowHelper
{
    public void Throw<this T>() // `this T` means extension method for T class
        where T : Exception, new()
        => throw new T();

    public void Throw<this T>(string  message, string paramName) // `this T` means extension method for T class
        where T : ArgumentException, new()
    {
        var ex = new T();
        ex.message = message;
        ex.param = paramName;
        throw ex;
    }
}

// Using

InvalidOperationException.Throw();
ArgumentOutOfRangeException.Throw("message", "param");

// Now without type extension methods

ThrowHelper.Throw<InvalidOperationException>;
ThrowHelper.Throw<ArgumentOutOfRangeException>("message", "param"); 

[colejohnson66]

#5497

[AlexRadch]

“Extension types” and “extension methods for type” are different ideas. Am I right?

[HaloFour]

Extension types are intended to expand upon what kind of extensions are permitted beyond current extension methods. I do believe that static extension methods are intended to be covered by that proposal, although this syntax is purely for illustration:

public static extension ConsoleExtensions for Console {
    public static void WriteHelllo() => Console.WriteLine("Hello!");
}

static class Program {
    static void Main() {
        Console.WriteHello();
    }
}

[AlexRadch]

https://github.com/dotnet/csharplang/blob/main/proposals/extensions.md

It will be wonderful! Moreover, they are offered as ('implicit' | 'explicit') 'extension'. I completely agree with this approach, as there are a huge number of other possibilities there.