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unordered_map
Defined in header <ctl/unordered_set.h>, CTL prefix uset, parent of unordered_map
Implementation in work still.
size_t int_hash(int* x) { return abs(*x); }
int int_eq(int* a, int* b) { return *a == *b; }
#undef POD
#define T int
#include <ctl/unordered_set.h>
uset_int a = uset_int_init(int_hash, int_eq);
for (int i=0; i < 120; i++)
uset_int_insert(&a, rand());
printf ("5 is %s included\n", uset_int_contains(&a, 5) ? "" : "not");
uset_digi_node* n = uset_int_find(&a, 5));
uset_int_erase(&a, 5);
foreach(uset_int, &a, it) { printf("GOT %d\n", *it.ref); }
foreach(uset_int, &a, it) { printf("SIZE %lu\n", uset_int_node_bucket_size(it.node)); }
printf("load_factor: %f\n", uset_int_load_factor(&a));
uset_int_free(&a);
unordered_set is an associative container (chained hash table) that contains a
set of unique objects of type Key. Search, insertion, and removal have average
constant-time complexity.
The function names are composed of the prefix uset_, the user-defined type
T and the method name. E.g uset_int with #define T int.
Internally, the elements are not sorted in any particular order, but organized into buckets. Which bucket an element is placed into depends entirely on the hash of its value. This allows fast access to individual elements, since once a hash is computed, it refers to the exact bucket the element is placed into.
We need the slow chained hash table to guarantee that pointers into nodes and values stay the same. For faster open-adressing hash tables an experimental hashtable container is planned. Container elements may not be modified since modification could change an element's hash and corrupt the container.
T value type
A being uset_T container type
B being uset_T_node node type
I being uset_T_it iterator type
init (T_hash(T*), T_equal(T*, T*))
constructs the hash table. with INTEGRAL types the member may be NULL, and are then set to default methods.
free (A* self)
destructs the hash table.
assign (A* self, A* other)
replaces the contents of the container.
copy (A* self)
returns a copy of the container.
begin (A* self)
returns an iterator to the beginning
end (A* self)
returns an iterator to the end
empty (A* self)
checks whether the container is empty
size (A* self)
returns the number of non-empty and non-deleted elements
bucket_count (A* self)
returns the size of the array. Same as capacity
max_size ()
returns the maximum possible number of elements
clear (A* self)
clears the contents
insert (A* self, T value)
inserts the element (C++17)
insert_found (A* self, T value, int* foundp)
inserts the element and sets foundp if it already existed.
emplace (A* self, T *value)
constructs elements in-place. (NYI)
emplace_hint (A* self, I* pos, T *value)
constructs elements in-place at position. (NYI)
emplace_found (A* self, T *value, int* foundp)
constructs elements in-place and sets foundp if it already existed. (NYI)
erase (A* self, T key)
erases the element by key
erase_if (A* self, int (*_match)(T*))
erases the element by match.
erase_range (A* self, I* first, I* last)
erases elements
swap (A* self, A* other)
swaps the contents
extract (A* self, T key)
extracts a node from the container. NYI
merge (A* self, A* other)
splices nodes from another container
Hash method int (*hash)(T*)
equal method int (*equal)(T*, T*)
count (A* self)
returns the number of elements matching specific key. It will always be 1, unless your equal method s broken.
find (A* self, T key)
finds element with specific key
contains (A* self, T key)
checks if the container contains element with specific key. (C++20)
equal (A* self, A* other)
equal_range (A* self, I* first, I* last)
if range of elements match a specific key. (NYI)
begin (A* self, size_t bucket_index)
returns an iterator to the beginning of the specified bucket (NYI)
end (A* self, size_t bucket_index)
returns an iterator to the end of the specified bucket (NYI)
bucket_count (A* self)
returns the number of buckets
max_bucket_count (A* self)
returns the maximum number of buckets of the set.
bucket_size (A* self, size_t bucket_index)
bucket_size (B* bucket)
returns the number of elements in the specific bucket, the collisions.
bucket (A* self, T value)
returns the bucket index for the key.
Growth policies:
#define CTL_USET_GROWTH_PRIMED
/* slower but more secure. uses all hash bits. (default) */
#define CTL_USET_GROWTH_POWER2
/* faster, but less secure. uses only some lower bits.
not recommended with public inet access (json, ...) */CTL_USET_GROWTH_POWER2 rehashes with bucket_count * 2,
CTL_USET_GROWTH_PRIMED rehashes with the next prime at bucket_count * 1.618.
load_factor (A* self)
returns average number of elements per bucket
max_load_factor (A* self)
set_max_load_factor (A* self, float factor)
manages maximum average number of elements per bucket. defaults to 0.85
rehash (A* self, size_t bucket_count)
reserves at least the specified number of buckets. This might regenerate the hash table, but not the buckets.
reserve (A* self, size_t desired_size)
reserves space for at least the specified number of elements. This might regenerate the hash table, but not the buckets.
swap (A* self)
specializes the swap algorithm
remove_if (A* self, int T_match(T*))
Removes all elements satisfying specific criteria.
find_if (A* self, int _match(T*))
finds element by predicate
find_if_not (A* self, int _match(T*))
finds element by predicate
intersection (A* self, A* other)
union (A* self, A* other)
difference (A* self, A* other)
symmetric_difference (A* self, A* other)
all_of (A* self, int _match(T*))
any_of (A* self, int _match(T*))
none_of (A* self, int _match(T*))
all_of_range (A* self, I* first, I* last, int _match(T*))
any_of_range (A* self, I* first, I* last, int _match(T*))
none_of_range (A* self, I* first, I* last, int _match(T*))