util.h

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#ifndef CSNIP_UTIL_H
#define CSNIP_UTIL_H
 
#include <string.h>
 
#define csnip_Tswap(type, a, b) \
        do { \
            type csnip_tmp =(a); \
            (a) = (b); \
            (b) = csnip_tmp; \
        } while(0)
 
#define csnip_Swap(a, b) \
        do { \
            typeof(a) csnip_tmp = (a); \
            (a) = (b); \
            (b) = csnip_tmp; \
        } while(0)
 
#define csnip_Cswap(a, b) \
        do { \
            _Static_assert(sizeof(a) == sizeof(b)); \
            char csnip_tmp[sizeof(a)]; \
            memcpy(csnip_tmp, &(a), sizeof(csnip_tmp)); \
            (a) = (b); \
            memcpy(&(b), csnip_tmp, sizeof(csnip_tmp)); \
        } while(0)
 
#define csnip_Min(a, b) \
        ((a) < (b) ? (a) : (b))
 
#define csnip_Max(a, b) \
        ((a) > (b) ? (a) : (b))
 
#define csnip_Static_len(a) (sizeof(a) / sizeof(*(a)))
 
inline size_t csnip_next_pow_of_2(size_t a)
{
    if (a == 0)
        return 1;
    --a;
    a |= a >> 1;
    a |= a >> 2;
    a |= a >> 4;
    a |= a >> 8;
    a |= a >> 16;
    if (sizeof(a) > 4)
        a |= a >> 32;
    ++a;
    return a;
}
 
#define csnip_Fill_n(dest, len, val) \
    do { \
        size_t csnip__n = (size_t)(len); \
        size_t csnip__i = 0; \
        for (; csnip__i < csnip__n; ++csnip__i) { \
            (dest)[csnip__i] = (val); \
        } \
    } while (0)
 
#define csnip_Fill(dest_begin, dest_end, val) \
    csnip_Fill_n(dest_begin, (dest_end) - (dest_begin), val)
 
#define csnip_Copy_n(src, len, dest) \
    do { \
        size_t csnip__n = (size_t)(len); \
        size_t csnip__i = 0; \
        for (; csnip__i < csnip__n; ++csnip__i) \
        { \
            (dest)[csnip__i] = (src)[csnip__i]; \
        } \
    } while (0)
 
#define csnip_Copy(src_begin, src_end, dest) \
    csnip_Copy_n(src_begin, (src_end) - (src_begin), dest)
 
#endif /* CSNIP_UTIL_H */
 
#if defined(CSNIP_SHORT_NAMES) && !defined(CSNIP_UTIL_HAVE_SHORT_NAMES)
#define Tswap           csnip_Tswap
#define Swap            csnip_Swap
#define Cswap           csnip_Cswap
#define Min         csnip_Min
#define Max         csnip_Max
#define Static_len      csnip_Static_len
#define next_pow_of_2       csnip_next_pow_of_2
#define Fill_n          csnip_Fill_n
#define Fill            csnip_Fill
#define Copy_n          csnip_Copy_n
#define Copy            csnip_Copy
#define CSNIP_UTIL_HAVE_SHORT_NAMES
#endif /* CSNIP_SHORT_NAMES && !CSNIP_UTIL_HAVE_SHORT_NAMES */