Luna/luna/CType.h

#pragma once

inline constexpr int _isascii(int c)
{
    return !(c & ~0x7f);
}

inline constexpr int _isblank(int c)
{
    return c == ' ' || c == '\t';
}

inline constexpr int _iscntrl(int c)
{
    return (unsigned int)c < 0x20 || c == 0x7f;
}

inline constexpr int _isdigit(int c)
{
    return c >= '0' && c < ':';
}

inline constexpr int _isgraph(int c)
{
    return (unsigned int)c - 0x21 < 0x5e;
}

inline constexpr int _islower(int c)
{
    return c >= 'a' && c < '{';
}

inline constexpr int _isupper(int c)
{
    return c >= 'A' && c < '[';
}

inline constexpr int _isprint(int c)
{
    return (unsigned int)c - 0x20 < 0x5f;
}

inline constexpr int _isalpha(int c)
{
    return _islower(c) || _isupper(c);
}

inline constexpr int _isalnum(int c)
{
    return _isalpha(c) || _isdigit(c);
}

inline constexpr int _ispunct(int c)
{
    return _isgraph(c) && !_isalnum(c);
}

inline constexpr int _isspace(int c)
{
    return c == ' ' || (unsigned int)c - '\t' < 5;
}

inline constexpr int _isxdigit(int c)
{
    return _isdigit(c) || ((unsigned int)c | 32) - 'a' < 6;
}

inline constexpr int _tolower(int c)
{
    if (_isupper(c)) return c | 32;
    return c;
}

inline constexpr int _toupper(int c)
{
    if (_islower(c)) return c & 0x5f;
    return c;
}

#if defined(_LUNA_OVERRIDE_STDC) || defined(IN_MOON)
#define isalnum _isalnum
#define isalpha _isalpha
#define isascii _isascii
#define iscntrl _iscntrl
#define isdigit _isdigit
#define isxdigit _isxdigit
#define isspace _isspace
#define ispunct _ispunct
#define isprint _isprint
#define isgraph _isgraph
#define islower _islower
#define isupper _isupper
#define isblank _isblank
#define tolower _tolower
#define toupper _toupper
#endif