28 Localization library [localization]

Effects: Classifies a character or sequence of characters.

For each argument character, identifies a value M of type ctype_­base​::​mask.

The second form identifies a value M of type ctype_­base​::​mask for each *p where (low <= p && p < high), and places it into vec[p - low].

Returns: The first form returns the result of the expression (M & m) != 0; i.e., true if the character has the characteristics specified.

The second form returns high.

Effects: Locates a character in a buffer that conforms to a classification m.

Returns: The smallest pointer p in the range [low, high) such that is(m, *p) would return true; otherwise, returns high.

Effects: Locates a character in a buffer that fails to conform to a classification m.

Returns: The smallest pointer p, if any, in the range [low, high) such that is(m, *p) would return false; otherwise, returns high.

Effects: Converts a character or characters to upper case.

The second form replaces each character *p in the range [low, high) for which a corresponding upper-case character exists, with that character.

Returns: The first form returns the corresponding upper-case character if it is known to exist, or its argument if not.

The second form returns high.

Effects: Converts a character or characters to lower case.

The second form replaces each character *p in the range [low, high) and for which a corresponding lower-case character exists, with that character.

Returns: The first form returns the corresponding lower-case character if it is known to exist, or its argument if not.

The second form returns high.

Effects: Applies the simplest reasonable transformation from a char value or sequence of char values to the corresponding charT value or values.260

The only characters for which unique transformations are required are those in the basic source character set.

For any named ctype category with a ctype <charT> facet ctc and valid ctype_­base​::​mask value M, (ctc.​is(M, c) || !is(M, do_­widen(c)) ) is true.261

The second form transforms each character *p in the range [low, high), placing the result in dest[p - low].

Returns: The first form returns the transformed value.

The second form returns high.

Effects: Applies the simplest reasonable transformation from a charT value or sequence of charT values to the corresponding char value or values.

For any character c in the basic source character set the transformation is such that

do_widen(do_narrow(c, 0)) == c

For any named ctype category with a ctype<char> facet ctc however, and ctype_­base​::​mask value M,

(is(M, c) || !ctc.is(M, do_narrow(c, dfault)) )

is true (unless do_­narrow returns dfault).

In addition, for any digit character c, the expression (do_­narrow(c, dfault) - '0') evaluates to the digit value of the character.

The second form transforms each character *p in the range [low, high), placing the result (or dfault if no simple transformation is readily available) in dest[p - low].

Returns: The first form returns the transformed value; or dfault if no mapping is readily available.

The second form returns high.