Allows you to treat strings as case insensitive

OrdinalIgnoreCaseString.cs

struct OrdinalIgnoreCaseString : IEquatable<OrdinalIgnoreCaseString>, IEquatable<string> {
    string _str;
    public OrdinalIgnoreCaseString(string str) {
        _str = str;
    }

    public static implicit operator OrdinalIgnoreCaseString(string str) {
        return new OrdinalIgnoreCaseString(str);
    }

    public static explicit operator string(OrdinalIgnoreCaseString str) {
        return str._str;
    }

    public bool Equals(string other) {
        return _str.Equals(other, StringComparison.OrdinalIgnoreCase);
    }

    public bool Equals(OrdinalIgnoreCaseString other) {
        return _str.Equals(other._str, StringComparison.OrdinalIgnoreCase);
    }
}

Source @KrzysztofCwalina on https://github.com/dotnet/corefx/issues/649 figured this could be better long lived.