Revised (in)equality operator articles

[pkulikov]

Snippets are moved to the samples repo: dotnet/samples#512

[BillWagner]

closing and reopening to build with new snippets

[BillWagner]

Overall, this is much improved @pkulikov The language is more clear and easier to understand.

I had one comment to address, and then this is ready to merge. I don't think we need a new sample for an enum comparison. I think it would be enough to say that == and != for enum types obey the same rules as the underlying integral type.

[BillWagner]

This should state that == is defined for enum types. That slipped through the cracks in the new (more clear) description.

[pkulikov]

@BillWagner indeed, as behavior for structs is described, enum case also should be stated explicitly. Thank you for the remark. I've added the clarification, please check the latest commit.

[BillWagner]

@pkulikov I'll suggest this small word change:

"Two operands of the same enum type are equal if the ..."

It's a small change, but the text you have could be misinterpreted to support something like the following:

    enum Color
    {
        Red,
        Green,
        Blue
    }

    enum Status
    {
        Red,
        Yellow,
        Green
    }

// compare two enum operands:
 bool equal = (Status.Red == Color.Red); // CS0019 (operator == cannot be applied to ...)

[pkulikov]

@BillWagner that's a good catch! Thanks. Fixed.

[BillWagner]

Thanks @pkulikov

This looks great. I'll as soon as the build finishes.