namespace std {
class ctype_base {
public:
using mask = see below;
static constexpr mask space = 1 << 0;
static constexpr mask print = 1 << 1;
static constexpr mask cntrl = 1 << 2;
static constexpr mask upper = 1 << 3;
static constexpr mask lower = 1 << 4;
static constexpr mask alpha = 1 << 5;
static constexpr mask digit = 1 << 6;
static constexpr mask punct = 1 << 7;
static constexpr mask xdigit = 1 << 8;
static constexpr mask blank = 1 << 9;
static constexpr mask alnum = alpha | digit;
static constexpr mask graph = alnum | punct;
};
}