Getting the max value of an enum

This is slightly nitpicky but the actual maximum value of any enum is Int32.MaxValue (assuming it's a enum derived from int). It's perfectly legal to cast any Int32 value to an any enum regardless of whether or not it actually declared a member with that value.

Legal:

enum SomeEnum
{
    Fizz = 42
}

public static void SomeFunc()
{
    SomeEnum e = (SomeEnum)5;
}

According to Matt Hamilton's answer, I thought on creating an Extension method for it.

Since ValueType is not accepted as a generic type parameter constraint, I didn't find a better way to restrict T to Enum but the following.

Any ideas would be really appreciated.

PS. please ignore my VB implicitness, I love using VB in this way, that's the strength of VB and that's why I love VB.

Howeva, here it is:

C#:

static void Main(string[] args)
{
    MyEnum x = GetMaxValue<MyEnum>(); //In newer versions of C# (7.3+)
    MyEnum y = GetMaxValueOld<MyEnum>();  
}

public static TEnum GetMaxValue<TEnum>()
  where TEnum : Enum
{
     return Enum.GetValues(typeof(TEnum)).Cast<TEnum>().Max();
}

//When C# version is smaller than 7.3, use this:
public static TEnum GetMaxValueOld<TEnum>()
  where TEnum : IComparable, IConvertible, IFormattable
{
    Type type = typeof(TEnum);

    if (!type.IsSubclassOf(typeof(Enum)))
        throw new
            InvalidCastException
                ("Cannot cast '" + type.FullName + "' to System.Enum.");

    return (TEnum)Enum.ToObject(type, Enum.GetValues(type).Cast<int>().Last());
}



enum MyEnum
{
    ValueOne,
    ValueTwo
}

VB:

Public Function GetMaxValue _
    (Of TEnum As {IComparable, IConvertible, IFormattable})() As TEnum

    Dim type = GetType(TEnum)

    If Not type.IsSubclassOf(GetType([Enum])) Then _
        Throw New InvalidCastException _
            ("Cannot cast '" & type.FullName & "' to System.Enum.")

    Return [Enum].ToObject(type, [Enum].GetValues(type) _
                        .Cast(Of Integer).Last)
End Function

Enum.GetValues() seems to return the values in order, so you can do something like this:

// given this enum:
public enum Foo
{
    Fizz = 3, 
    Bar = 1,
    Bang = 2
}

// this gets Fizz
var lastFoo = Enum.GetValues(typeof(Foo)).Cast<Foo>().Last();

Edit

For those not willing to read through the comments: You can also do it this way:

var lastFoo = Enum.GetValues(typeof(Foo)).Cast<Foo>().Max();

... which will work when some of your enum values are negative.

I agree with Matt's answer. If you need just min and max int values, then you can do it as follows.

Maximum:

Enum.GetValues(typeof(Foo)).Cast<int>().Max();

Minimum:

Enum.GetValues(typeof(Foo)).Cast<int>().Min();