How to write a generic function for enum types

Question

 //TechTeam is enum type
 //This line returns the enumvalue as out param, for the matching stringvalue.

 Enum.TryParse(stringvalue, out TechTeam tt);

It works perfectly. Now if I turn it to generic I am using

private T enumparse<T>(string state)
    {
        Enum.TryParse<T>(state, out T stateout);
        return stateout;
    }

it throws error.

I changed the code to :

 private T? enumparse<T>(string? state) where T: System.Enum
    {
        Enum.TryParse<T>(state, out T stateout);
        return stateout;
    }

It says the Type T must be a non nullable value.

The accepted answer is incomplete, though, as it could allow `System.Enum` itself. You also need the `struct` constraint to prevent `System.Enum` from being allowed. [This answer](https://stackoverflow.com/a/28527552) is the one that's complete and correct. — madreflection, Jun 02 '23 at 16:27
"it throws error" is never sufficient information in a Stack Overflow question. Always *always* provide the details of the error. — Jon Skeet, Jun 02 '23 at 16:29

score 0 · Answer 1 · answered Jun 02 '23 at 16:26

0

Did you try setting a type constraint? I'm pretty sure there is a variation that can work with Enum.

private T enumparse<T>(string state) where T : struct, Enum
{
    Enum.TryParse<T>(state, out T stateout);
    return stateout;
}

answered Jun 02 '23 at 16:26

Jonathan Wood

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How to write a generic function for enum types

1 Answers1