1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */ 2 /* 3 * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. 4 * 5 * Specialized constant-time ctype.h reimplementations that aren't locale-specific. 6 */ 7 8 #ifndef CTYPE_H 9 #define CTYPE_H 10 11 #include <stdbool.h> 12 13 static inline bool char_is_space(int c) 14 { 15 unsigned char d = c - 9; 16 return (0x80001FU >> (d & 31)) & (1U >> (d >> 5)); 17 } 18 19 static inline bool char_is_digit(int c) 20 { 21 return (unsigned int)(('0' - 1 - c) & (c - ('9' + 1))) >> (sizeof(c) * 8 - 1); 22 } 23 24 static inline bool char_is_alpha(int c) 25 { 26 return (unsigned int)(('a' - 1 - (c | 32)) & ((c | 32) - ('z' + 1))) >> (sizeof(c) * 8 - 1); 27 } 28 29 #endif 30