From 8efca839fc616573bbc5d05ce6e6d8b87991ae93 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Sat, 20 Feb 2016 22:24:08 +0100 Subject: add bsearch MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- include/stdlib.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'include') diff --git a/include/stdlib.h b/include/stdlib.h index f68c046..d3e07f8 100644 --- a/include/stdlib.h +++ b/include/stdlib.h @@ -343,6 +343,36 @@ char* getenv(const char*) __GCC_ONLY(__attribute__((__warn_unused_result__, __nonnull__))); +/** + * Search for an item in a sorted list of comparable + * elements. The list must be sorted in ascending order. + * The function usually implements binary search, + * as is done in this implementation. + * + * @etymology (B)inary (search). + * + * @param sought The sought item. + * @param list The beginning of the list to search. + * @param n The number of elements in the list. + * @param width The width, in bytes, of each element in the list. + * @param compar A function that shall compare two items, and return + * a value less than, equal to, or greater than zero + * if the first argument is less than, equal to, or + * greater than the second argument, respectively. + * @return The address of an arbritrart element in `list` that + * is equal to `sought`, or `NULL` if no such element + * can be found (does not exist, or because `list` + * is not properly sorted.) + * + * @since Always. + */ +void* bsearch(const void*, const void*, size_t, size_t, int (*)(const void*, const void*)) + __GCC_ONLY(__attribute__((__warn_unused_result__, __nonnull__(1, 5), __pure__))); +#ifdef __CONST_CORRECT +# define bsearch(...) (__const_correct2(bsearch, __VA_ARGS__)) +#endif + + /* TODO implement rand-functions */ #define RAND_MAX 1 -- cgit v1.2.3-70-g09d2