public static int Compare(this string strA, string strB);
public static int Compare(this string strA, string strB, bool ignoreCase);
public static int Compare(this string strA, string strB, System.StringComparison comparisonType);
public static int Compare(this string strA, string strB, bool ignoreCase, System.Globalization.CultureInfo culture);
public static int Compare(this string strA, int indexA, string strB, int indexB, int length);
public static int Compare(this string strA, int indexA, string strB, int indexB, int length, bool ignoreCase);
public static int Compare(this string strA, int indexA, string strB, int indexB, int length, System.StringComparison comparisonType);
public static int Compare(this string strA, int indexA, string strB, int indexB, int length, bool ignoreCase, System.Globalization.CultureInfo culture);
public static int CompareOrdinal(this string strA, string strB);
public static int CompareOrdinal(this string strA, int indexA, string strB, int indexB, int length);
public static string Concat(this string str0, string str1);
public static string Concat(this string str0, string str1, string str2);
public static string Concat(this string str0, string str1, string str2, string str3);
public static string Copy(this string str);
public static string Intern(this string str);
public static string IsInterned(this string str);
public static bool IsNullOrEmpty(this string value);