namespace System
{
    public readonly struct Char : IAdditionOperators<char, char, char>, IAdditiveIdentity<char, char>, IBinaryInteger<char>, IBinaryNumber<char>, IBitwiseOperators<char, char, char>, IComparable, IComparable<char>, IComparisonOperators<char, char>, IConvertible, IDecrementOperators<char>, IDivisionOperators<char, char, char>, IEqualityOperators<char, char>, IEquatable<char>, IFormattable, IIncrementOperators<char>, IMinMaxValue<char>, IModulusOperators<char, char, char>, IMultiplicativeIdentity<char, char>, IMultiplyOperators<char, char, char>, INumber<char>, IParseable<char>, IShiftOperators<char, char>, ISpanFormattable, ISpanParseable<char>, ISubtractionOperators<char, char, char>, IUnaryNegationOperators<char, char>, IUnaryPlusOperators<char, char>, IUnsignedNumber<char>
    {
        public static bool IsAscii(char c);
    }
}