cosmopolitan/libc/alg/reverse.h
Justine Tunney ea0b5d9d1c Get Cosmopolitan into releasable state
A new rollup tool now exists for flattening out the headers in a way
that works better for our purposes than cpp. A lot of the API clutter
has been removed. APIs that aren't a sure thing in terms of general
recommendation are now marked internal.

There's now a smoke test for the amalgamation archive and gigantic
header file. So we can now guarantee you can use this project on the
easiest difficulty setting without the gigantic repository.

A website is being created, which is currently a work in progress:
https://justine.storage.googleapis.com/cosmopolitan/index.html
2020-11-25 08:19:00 -08:00

31 lines
1 KiB
C

#ifndef COSMOPOLITAN_LIBC_ALG_REVERSE_H_
#define COSMOPOLITAN_LIBC_ALG_REVERSE_H_
#include "libc/bits/xchg.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
/**
* Reverses array.
*
* @param ARRAY is a typed array or a pointer to one
* @param COUNT is the number of items
* @return pointer to start of array
* @see ARRAYLEN()
*/
#define reverse(ARRAY, COUNT) \
({ \
autotype(&(ARRAY)[0]) Array = (ARRAY); \
size_t Count = (COUNT); \
if (Count) { \
size_t Start = 0; \
size_t End = Count - 1; \
while (Start < End) { \
xchg(&Array[Start], &Array[End]); \
++Start; \
--End; \
} \
} \
Array; \
})
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_ALG_REVERSE_H_ */