3.1.0

• Additional overloads for TextEncodingConverter.GetEncoding:

public static Encoding GetEncoding(string?, EncoderFallback, DecoderFallback);
public static Encoding GetEncoding(int);
public static Encoding GetEncoding(int, EncoderFallback, DecoderFallback);

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• New extension methods for the String class:

public static bool ContainsWhiteSpace(this string? s);
public static bool ContainsAny(this string, char, char);
public static bool ContainsAny(this string, char, char, char);
public static bool ContainsAny(this string, ReadOnlySpan<char>);
public static bool ContainsAny(this string, char[]);
public static int IndexOfAny(this string, ReadOnlySpan<char>, int, int);
public static int LastIndexOfAny(this string, ReadOnlySpan<char>, int, int)

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• New extension methods for the StringBuilder Class:

public static bool Contains(this StringBuilder, char);
public static int IndexOf(this StringBuilder, char);
public static int IndexOf(this StringBuilder, char, int);
public static int IndexOf(this StringBuilder, char, int, int);
public static int LastIndexOf(this StringBuilder, char);
public static int LastIndexOf(this StringBuilder, char, int);
public static int LastIndexOf(this StringBuilder, char, int, int);

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• New extension methods for the ReadOnlySpan<Char> structure:

public static bool ContainsAny(this ReadOnlySpan<char>, char, char );
public static bool ContainsAny(this ReadOnlySpan<char>, char, char, char );
public static int IndexOfAny (this ReadOnlySpan<char>, ReadOnlySpan<char>);
public static int LastIndexOfAny (this ReadOnlySpan<char>, ReadOnlySpan<char>);
public static bool ContainsWhiteSpace(this ReadOnlySpan<char> span);

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• New polyfill for .NET Framework 4.5 and .NET Standard 2.0:

public static StringBuilder Append(this StringBuilder, StringBuilder?, int, int);