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LandR

I've used tuples in the past when a method could fail and I want the error code back or I want the thing.

e.g.

(string errorCode, Quax result) TryGetAQuax();

Oh, to have Either / Discrimated Unions in C# :(

We also can't use this at work, we are still having to target 4.5.1 :(

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> Oh, to have Either / Discrimated Unions in C# :(

Here you go: https://sourceforge.net/p/sasa/code/ci/dotnet-standard/tree/...

You can use it like:

    Either<string, int> x = 99;
    if (x.TryCase1(out var s))
        ...
    else if (x.TryCase2(out var i))
        ...

Only up to 4 cases are included because beyond that, I think you should define a custom type.

Although I should note that C# now supports special casting via the 'is' operator, so you can now just do this:

    object x = 99;
    if (x is string s))
        ... do something with 's'
    else if (x is int i))
        ... do something with 'i'

There's also the OneOf NuGet package [1] which I've put to good use in a number of projects. Using `object` and `is` means you can't enforce what types get passed in, nor can you ensure that all possible types actually get handled.

[1]: https://github.com/mcintyre321/OneOf/

I can never justify the use of delegates for pattern matching purposes. It's just way too much overhead, and so would discourage the use of these abstractions.

> when a method could fail and I want the error code back or I want the thing

For this use case, I mostly use a Result<T> with .Status, .Messages, .Exception, .Data etc properties.

You can :) (Especially with the pattern matching feature) https://github.com/louthy/language-ext

Could you use the System.ValueTuple NuGet package?

Requires 4.6.1

Also works with .NET 4.5. System.ValueTuple package has .NET Standard 1.0 target which can be effortlessly used by a .NET 4.5 assembly.

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