mirror of
https://github.com/JakeHillion/drgn.git
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b450a7b02b
For many use cases of vectors, a full size_t isn't necessary, and might even be unnecessary memory overhead. Allow using any unsigned integer type no larger than size_t, but continue to default to size_t. Signed-off-by: Omar Sandoval <osandov@osandov.com>
624 lines
19 KiB
C
624 lines
19 KiB
C
// Copyright (c) Meta Platforms, Inc. and affiliates.
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// SPDX-License-Identifier: LGPL-2.1-or-later
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/**
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* @file
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*
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* Dynamic arrays.
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*
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* See @ref Vectors.
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*/
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#ifndef DRGN_VECTOR_H
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#define DRGN_VECTOR_H
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#include <stdbool.h>
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#include <stdlib.h> // IWYU pragma: keep
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#include <string.h> // IWYU pragma: keep
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#include "generics.h"
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#include "minmax.h"
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#include "util.h"
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#include "pp.h"
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/**
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* @ingroup Internals
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*
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* @defgroup Vectors Vectors
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*
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* Dynamic arrays (a.k.a.\ vectors).
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*
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* This is an implementation of generic, strongly-typed vectors.
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*
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* A vector is defined with @ref DEFINE_VECTOR(). Each generated vector
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* interface is prefixed with a given name; the interface documented here uses
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* the example name @c vector.
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*
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* @{
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*/
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#ifdef DOXYGEN
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/**
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* @struct vector
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*
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* Vector instance.
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*
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* There are no requirements on how this is allocated; it may be global, on the
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* stack, allocated by @c malloc(), embedded in another structure, etc.
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*/
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struct vector;
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/**
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* Initialize a @ref vector.
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*
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* The new vector is empty.
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*
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* @sa VECTOR_INIT
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*/
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void vector_init(struct vector *vector);
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/** Free memory allocated by a @ref vector. */
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void vector_deinit(struct vector *vector);
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/** Return the number of entries in a @ref vector. */
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size_type vector_size(const struct vector *vector);
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/** Return whether a @ref vector is empty. */
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bool vector_empty(const struct vector *vector);
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/**
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* Maximum possible number of entries in a @ref vector.
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*
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* Attempts to increase the size or capacity beyond this will fail.
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*/
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const size_type vector_max_size;
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/**
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* Update the number of entries in a @ref vector.
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*
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* If @p size is greater than the current capacity, this increases the capacity
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* to at least @p size and reallocates the entries.
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*
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* If @p size is greater than the current size, the entries between the old size
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* and the new size are uninitialized.
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*
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* @return @c true on success, @c false on failure.
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*/
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bool vector_resize(struct vector *vector, size_t size);
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/**
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* Set the size of a @ref vector to zero.
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*
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* This does not change the capacity or free the entries.
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*/
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void vector_clear(struct vector *vector);
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/** Return the number of allocated entries in a @ref vector. */
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size_type vector_capacity(const struct vector *vector);
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/**
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* Increase the capacity of a @ref vector.
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*
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* If @p capacity is greater than the current capacity, this increases the
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* capacity to at least @p capacity and reallocates the entries. Otherwise, it
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* does nothing.
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*
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* @return @c true on success, @c false on failure.
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*/
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bool vector_reserve(struct vector *vector, size_t capacity);
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/**
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* Increase the capacity of a @ref vector to accomodate at least one append.
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*
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* If the current capacity is equal to the current size, this increases the
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* capacity by at least one and reallocates the entries. Otherwise, it does
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* nothing.
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*
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* @return @c true on success, @c false on failure.
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*/
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bool vector_reserve_for_append(struct vector *vector);
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/**
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* Increase the capacity of a @ref vector to accomodate at least @p n appends.
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*
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* If the current capacity minus the current size is not at least @p n, this
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* increases the capacity by at least @p n and reallocates the entries.
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* Otherwise, it does nothing.
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*
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* @return @c true on success, @c false on failure.
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*/
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bool vector_reserve_for_extend(struct vector *vector, size_t n);
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/**
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* Free unused memory in a @ref vector.
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*
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* This may reduce the capacity and reallocate the entries. It may also do
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* nothing.
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*/
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void vector_shrink_to_fit(struct vector *vector);
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/**
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* Steal the array of entries from a @ref vector.
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*
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* This returns the internal array of entries. The vector can no longer be used
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* except to be passed to @ref vector_deinit(), which will do nothing.
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*
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* This is undefined if the vector type was defined with a non-zero @c
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* inline_size.
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*
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* This can be used to build an array when the size isn't known ahead of time
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* but won't change after the array is built. For example:
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*
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* ```
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* DEFINE_VECTOR(int_vector, int);
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*
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* bool primes_less_than(int n, int **array_ret, size_t *size_ret)
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* {
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*
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* _cleanup_(int_vector_deinit) struct int_vector vector = VECTOR_INIT;
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* for (int i = 2; i < n; i++) {
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* if (is_prime(i) && !int_vector_push(&vector, &i))
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* return false;
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* }
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* int_vector_shrink_to_fit(&vector);
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* int_vector_steal(&vector, array_ret, size_ret);
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* return true;
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* }
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* ```
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*
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* As demonstrated here, it may be desirable to call @ref vector_shrink_to_fit()
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* first.
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*
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* @param[out] entries_ret Returned array. This must be freed with @c free().
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* @param[out] size_ret Returned number of entries in array. May be @c NULL.
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*/
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void vector_steal(struct vector *vector, entry_type **entries_ret,
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size_type *size_ret);
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/**
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* Return the array of entries in a @ref vector.
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*
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* The vector may be empty, in which case this is equal to `vector_end(vector)`.
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*/
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entry_type *vector_begin(struct vector *vector);
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/**
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* Return one past the last entry in a @ref vector.
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*
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* The vector may be empty, in which case this is equal to
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* `vector_begin(vector)`.
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*/
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entry_type *vector_end(struct vector *vector);
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/**
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* Return the first entry in a @ref vector.
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*
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* This is equivalent to `vector_at(vector, 0)`. The vector must not be empty
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* (in contrast to @ref vector_begin()).
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*/
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entry_type *vector_first(struct vector *vector);
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/**
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* Return the last entry in a @ref vector.
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*
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* This is equivalent to `vector_at(vector, vector_size(vector) - 1)`. The
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* vector must not be empty.
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*/
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entry_type *vector_last(struct vector *vector);
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/**
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* Return the entry at the given index in a @ref vector.
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*
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* @param[in] i Entry index. Must be less than the size of the vector.
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*/
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entry_type *vector_at(struct vector *vector, size_t i);
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/**
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* Append to a @ref vector.
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*
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* This increases vector's size by one. If the current capacity is equal to the
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* current size, this increases the capacity by at least one and reallocates the
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* entries.
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*
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* @return @c true on success, @c false on failure.
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*/
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bool vector_append(struct vector *vector, const entry_type *entry);
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/**
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* Append an uninitialized entry to a @ref vector.
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*
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* Like @ref vector_append(), but return a pointer to the new (uninitialized)
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* entry.
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*
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* @return The new entry on success, @c NULL on failure.
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*/
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entry_type *vector_append_entry(struct vector *vector);
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/**
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* Append all of the entries from one vector to another.
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*
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* @param[in] dst Vector to append to.
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* @param[in] src Source vector. This is not modified.
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* @return @c true on success, @c false on failure.
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*/
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bool vector_extend(struct vector *dst, const struct vector *src);
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/**
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* Remove and return the last entry in a @ref vector.
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*
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* The vector must not be empty. This decreases the size by one. It does not
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* change the capacity or reallocate the entries.
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*
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* @return A pointer to the removed entry, which remains valid until another
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* entry is inserted in its place or the entries are reallocated.
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*/
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entry_type *vector_pop(struct vector *vector);
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#endif
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/**
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* Inline as many entries as possible without making the vector type larger than
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* if @c inline_size was 0.
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*
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* This can be passed as the @c inline_size argument to @ref DEFINE_VECTOR().
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*/
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#define vector_inline_minimal -1
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/**
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* Define a vector type without defining its functions.
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*
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* This is useful when the vector type must be defined in one place (e.g., a
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* header) but the interface is defined elsewhere (e.g., a source file) with
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* @ref DEFINE_VECTOR_FUNCTIONS(). Otherwise, just use @ref DEFINE_VECTOR().
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*
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* This takes the same arguments as @ref DEFINE_VECTOR().
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*/
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#define DEFINE_VECTOR_TYPE(...) \
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PP_OVERLOAD(DEFINE_VECTOR_TYPE_I, __VA_ARGS__)(__VA_ARGS__)
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#define DEFINE_VECTOR_TYPE_I2(vector, entry_type) \
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DEFINE_VECTOR_TYPE_I3(vector, entry_type, 0)
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#define DEFINE_VECTOR_TYPE_I3(vector, entry_type, inline_size) \
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DEFINE_VECTOR_TYPE_I4(vector, entry_type, inline_size, size_t)
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#define DEFINE_VECTOR_TYPE_I4(vector, entry_type, inline_size, size_type) \
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typedef typeof(entry_type) vector##_entry_type; \
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\
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typedef typeof(size_type) vector##_size_type; \
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_Static_assert((vector##_size_type)-1 > 0, "size_type must be unsigned"); \
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_Static_assert((vector##_size_type)-1 <= SIZE_MAX, \
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"size_type must not be larger than size_t"); \
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\
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enum { vector##_inline_size_arg = (inline_size) }; \
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/* \
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* If the vector was defined with a zero inline size, then we don't want to \
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* require the complete definition of the entry type, so we do this to stub it \
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* out. \
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*/ \
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typedef_if(vector##_inline_entry_type, vector##_inline_size_arg == 0, void *, \
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vector##_entry_type); \
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enum { \
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vector##_inline_size = \
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vector##_inline_size_arg == vector_inline_minimal \
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? sizeof(void *) / sizeof(vector##_inline_entry_type) \
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: vector##_inline_size_arg, \
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/* Used to avoid a zero-length array. */ \
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vector##_inline_size_non_zero = \
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vector##_inline_size == 0 ? 1 : vector##_inline_size, \
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}; \
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\
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struct vector { \
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union { \
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vector##_entry_type *_data; \
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/* \
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* If the vector has no inline entries, then we want this to \
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* degrade to (entry_type *) instead of (entry_type [0]) so that\
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* the vector is not over-aligned to alignof(entry_type) and to \
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* avoid zero-length arrays. \
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*/ \
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type_if(vector##_inline_size == 0, vector##_entry_type *, \
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vector##_inline_entry_type [vector##_inline_size_non_zero])\
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_idata; \
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}; \
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vector##_size_type _size; \
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vector##_size_type _capacity; \
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}; \
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struct DEFINE_VECTOR_needs_semicolon
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/**
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* Define the functions for a vector.
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*
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* The vector type must have already been defined with @ref
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* DEFINE_VECTOR_TYPE().
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*
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* Unless the type and function definitions must be in separate places, use @ref
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* DEFINE_VECTOR() instead.
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*
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* @sa DEFINE_VECTOR()
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*/
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#define DEFINE_VECTOR_FUNCTIONS(vector) \
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__attribute__((__unused__)) \
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static void vector##_init(struct vector *vector) \
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{ \
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if (vector##_inline_size == 0) \
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vector->_data = NULL; \
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vector->_size = vector->_capacity = 0; \
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} \
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\
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static bool vector##_is_inline(const struct vector *vector) \
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{ \
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return vector##_inline_size > 0 && vector->_capacity == 0; \
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} \
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\
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__attribute__((__unused__)) \
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static void vector##_deinit(struct vector *vector) \
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{ \
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if (!vector##_is_inline(vector)) \
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free(vector->_data); \
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} \
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\
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__attribute__((__unused__)) \
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static vector##_size_type vector##_size(const struct vector *vector) \
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{ \
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return vector->_size; \
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} \
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\
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__attribute__((__unused__)) \
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static bool vector##_empty(const struct vector *vector) \
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{ \
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return vector->_size == 0; \
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} \
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\
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static const vector##_size_type vector##_max_size = \
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min_iconst(PTRDIFF_MAX, (vector##_size_type)-1) \
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/ sizeof(vector##_entry_type); \
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\
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static vector##_size_type vector##_capacity(const struct vector *vector) \
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{ \
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if (vector##_is_inline(vector)) \
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return vector##_inline_size; \
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return vector->_capacity; \
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} \
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\
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static bool vector##_reallocate(struct vector *vector, size_t capacity) \
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{ \
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void *new_data; \
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if (vector##_is_inline(vector)) { \
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new_data = malloc(capacity * sizeof(vector##_entry_type)); \
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if (!new_data) \
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return false; \
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memcpy(new_data, vector->_idata, \
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vector##_size(vector) * sizeof(vector##_entry_type)); \
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} else { \
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new_data = realloc(vector->_data, \
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capacity * sizeof(vector##_entry_type)); \
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if (!new_data) \
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return false; \
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} \
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vector->_data = new_data; \
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vector->_capacity = capacity; \
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return true; \
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} \
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\
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static bool vector##_reserve_for_extend(struct vector *vector, size_t n) \
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{ \
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vector##_size_type size = vector##_size(vector); \
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/* \
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* Cast to size_t to avoid -Wsign-error if size_type is promoted to int.\
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*/ \
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if (n <= (size_t)(vector##_capacity(vector) - size)) \
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return true; \
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if (n > (size_t)(vector##_max_size - size)) \
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return false; \
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vector##_size_type new_capacity = size + (n > size ? n : size); \
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if (new_capacity < size || new_capacity > vector##_max_size) \
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new_capacity = vector##_max_size; \
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return vector##_reallocate(vector, new_capacity); \
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} \
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\
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__attribute__((__unused__)) \
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static bool vector##_resize(struct vector *vector, size_t size) \
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{ \
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if (vector->_size < size \
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&& !vector##_reserve_for_extend(vector, size - vector->_size)) \
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return false; \
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vector->_size = size; \
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return true; \
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} \
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\
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__attribute__((__unused__)) \
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static void vector##_clear(struct vector *vector) \
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{ \
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vector->_size = 0; \
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} \
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\
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__attribute__((__unused__)) \
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static bool vector##_reserve(struct vector *vector, size_t capacity) \
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{ \
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if (capacity <= vector##_capacity(vector)) \
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return true; \
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if (capacity > vector##_max_size) \
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return false; \
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return vector##_reallocate(vector, capacity); \
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} \
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\
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static bool vector##_reserve_for_append(struct vector *vector) \
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{ \
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return vector##_reserve_for_extend(vector, 1); \
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} \
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\
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__attribute__((__unused__)) \
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static void vector##_shrink_to_fit(struct vector *vector) \
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{ \
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vector##_size_type size = vector##_size(vector); \
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if (vector->_capacity <= size) \
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return; \
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if (size > vector##_inline_size) { \
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vector##_reallocate(vector, size); \
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} else if (vector##_inline_size > 0) { \
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void *old_data = vector->_data; \
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memcpy(vector->_idata, old_data, \
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size * sizeof(vector##_entry_type)); \
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free(old_data); \
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vector->_capacity = 0; \
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} else { \
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free(vector->_data); \
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vector->_data = NULL; \
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vector->_capacity = 0; \
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} \
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} \
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\
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/* \
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* If the vector was defined with a non-zero inline size, make vector_steal() \
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* fail at compile time by having it take a dummy type incompatible with struct \
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* vector (but close enough to the real thing so the function body compiles). \
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*/ \
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struct vector##_steal_is_undefined_for_non_zero_inline_size { \
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void *_data; \
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vector##_size_type _size; \
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}; \
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__attribute__((__unused__)) \
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static void vector##_steal(type_if(vector##_inline_size_arg == 0, \
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struct vector, \
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struct vector##_steal_is_undefined_for_non_zero_inline_size)\
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*vector, \
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vector##_entry_type **entries_ret, \
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vector##_size_type *size_ret) \
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{ \
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*entries_ret = vector->_data; \
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if (size_ret) \
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*size_ret = vector->_size; \
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vector->_data = NULL; \
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} \
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\
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static vector##_entry_type *vector##_begin(struct vector *vector) \
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{ \
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if (vector##_is_inline(vector)) \
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return vector->_idata; \
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return vector->_data; \
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} \
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\
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__attribute__((__unused__)) \
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static vector##_entry_type *vector##_end(struct vector *vector) \
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{ \
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return add_to_possibly_null_pointer(vector##_begin(vector), \
|
|
vector##_size(vector)); \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static vector##_entry_type *vector##_first(struct vector *vector) \
|
|
{ \
|
|
return vector##_begin(vector); \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static vector##_entry_type *vector##_last(struct vector *vector) \
|
|
{ \
|
|
return vector##_begin(vector) + vector##_size(vector) - 1; \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static vector##_entry_type *vector##_at(struct vector *vector, size_t i) \
|
|
{ \
|
|
return vector##_begin(vector) + i; \
|
|
} \
|
|
\
|
|
static vector##_entry_type *vector##_append_entry(struct vector *vector) \
|
|
{ \
|
|
if (!vector##_reserve_for_append(vector)) \
|
|
return NULL; \
|
|
return vector##_begin(vector) + vector->_size++; \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static bool vector##_append(struct vector *vector, \
|
|
const vector##_entry_type *entry) \
|
|
{ \
|
|
vector##_entry_type *new_entry = vector##_append_entry(vector); \
|
|
if (!new_entry) \
|
|
return false; \
|
|
memcpy(new_entry, entry, sizeof(*entry)); \
|
|
return true; \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static bool vector##_extend(struct vector *dst, const struct vector *src) \
|
|
{ \
|
|
if (src->_size == 0) \
|
|
return true; \
|
|
if (!vector##_reserve_for_extend(dst, src->_size)) \
|
|
return false; \
|
|
memcpy(vector##_end(dst), vector##_begin((struct vector *)src), \
|
|
src->_size * sizeof(vector##_entry_type)); \
|
|
dst->_size += src->_size; \
|
|
return true; \
|
|
} \
|
|
\
|
|
__attribute__((__unused__)) \
|
|
static vector##_entry_type *vector##_pop(struct vector *vector) \
|
|
{ \
|
|
return vector##_begin(vector) + --vector->_size; \
|
|
} \
|
|
struct DEFINE_VECTOR_needs_semicolon
|
|
|
|
/**
|
|
* Define a vector interface.
|
|
*
|
|
* This macro defines a vector type along with its functions. It accepts a
|
|
* variable number of arguments:
|
|
*
|
|
* ```
|
|
* DEFINE_VECTOR(vector, entry_type);
|
|
* DEFINE_VECTOR(vector, entry_type, inline_size);
|
|
* DEFINE_VECTOR(vector, entry_type, inline_size, size_type);
|
|
* ```
|
|
*
|
|
* @param[in] vector Name of the type to define. This is prefixed to all of the
|
|
* types and functions defined for that type.
|
|
* @param[in] entry_type Type of entries in the vector.
|
|
* @param[in] inline_size Number of entries to store directly in the vector type
|
|
* instead of as a separate allocation, or @ref vector_inline_minimal. The
|
|
* default is 0. If this is not 0, then the complete definition of @p entry_type
|
|
* must be available.
|
|
* @param[in] size_type Unsigned integer type to use to store size and capacity.
|
|
* The default is `size_t`.
|
|
*/
|
|
#define DEFINE_VECTOR(vector, ...) \
|
|
DEFINE_VECTOR_TYPE(vector, __VA_ARGS__); \
|
|
DEFINE_VECTOR_FUNCTIONS(vector)
|
|
|
|
/**
|
|
* Empty vector initializer.
|
|
*
|
|
* This can be used to initialize a vector when declaring it.
|
|
*
|
|
* @sa vector_init()
|
|
*/
|
|
#define VECTOR_INIT { { 0 } }
|
|
|
|
/**
|
|
* Iterate over every entry in a @ref vector.
|
|
*
|
|
* This is roughly equivalent to
|
|
*
|
|
* ```
|
|
* for (entry_type *it = vector_begin(vector), *end = vector_end(vector);
|
|
* it != end; it++)
|
|
* ```
|
|
*
|
|
* Except that @p vector is only evaluated once.
|
|
*
|
|
* @param[in] vector_type Name of vector type.
|
|
* @param[out] it Name of iteration variable.
|
|
* @param[in] vector Vector to iterate over.
|
|
*/
|
|
#define vector_for_each(vector_type, it, vector) \
|
|
for (vector_type##_entry_type *it, \
|
|
*it##__end = ({ \
|
|
struct vector_type *it##__vector = (vector); \
|
|
it = vector_type##_begin(it##__vector); \
|
|
vector_type##_end(it##__vector); \
|
|
}); \
|
|
it != it##__end; it++)
|
|
|
|
/** @} */
|
|
|
|
#endif /* DRGN_VECTOR_H */
|