Defines the macros traditionally defined in the Standard C library header <ctype.h>.
#if <TRADITIONAL C HEADERS>
#include <ctype.h>
namespace std {
using ::isalnum;
using ::isalpha;
using ::iscntrl;
using ::isdigit;
using ::isgraph;
using ::islower;
using ::isprint;
using ::ispunct;
using ::isspace;
using ::isupper;
using ::isxdigit;
using ::tolower;
using ::toupper;
}
#undef isalnum
#undef isalpha
#undef isblank
#undef iscntrl
#undef isdigit
#undef isgraph
#undef islower
#undef isprint
#undef ispunct
#undef isspace
#undef isupper
#undef isxdigit
#undef tolower
#undef toupper
#endif
Remarks
Including this header also ensures that the names declared with external linkage in the Standard C library header are declared in the std namespace. In this implementation, the names may or may not also be declared in the global namespace, depending on the specific translation environment.