How to pass generic type as parameter to Enum.Parse()-CodePudding

I have a class with a generic method:

public record OperationCollectionGeneric<OPERATIONTYPE> where OPERATIONTYPE: notnull, Enum
{
    public OPERATIONTYPE Group { get; }

    public OperationCollectionGeneric(string part1, string? part2 = null, string? part3 = null)
    {
        Group = Enum.Parse<OPERATIONTYPE>(part1, true);
    }

The Enum.Parse() method has the following error:

Error CS0453 The type 'OPERATIONTYPE' must be a non-nullable value type in order to use it as parameter 'TEnum' in the generic type or method 'Enum.Parse(ReadOnlySpan, bool)'

How can I pass the make sure that OPERATIONTYPE parameter is of type Enum

I tried to use the where keywork to set the enum type for the OPERATIONTYPE but it does not work.

CodePudding user response：

Enum.Parse is restricted to struct's, so change generic constraints to match it:

public record OperationCollectionGeneric<OPERATIONTYPE> where OPERATIONTYPE : struct, Enum

CodePudding user response：

OPERATIONTYPE must be a non-nullable value type, but System.Enum is a reference type.