I Made a Better Dynamic Array than stb_ds.h

vector.h - Type-Safe Dynamic Arrays for C

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A production-ready, macro-based vector library to generate type-safe dynamic arrays.

#include "vector.h"

VECTOR_DECLARE(IntVector, int_vector, int)
VECTOR_DEFINE(IntVector, int_vector, int)

int main(void) {
	IntVector nums = {0};

	int_vector_push(&nums, 42);
	int_vector_push(&nums, 13);

	printf("First: %d\n", int_vector_get(&nums, 0));  /* 42 */
	printf("Size: %zu\n", VECTOR_SIZE(&nums));        /* 2 */

	int_vector_free(&nums);
	return 0;
}

Features

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• Type-safe: Generate vectors for any type
• Portable: C89 compatible, tested on GCC/Clang/MSVC/ICX across x86_64/ARM64
• Robust: Comprehensive bounds checking and memory management
• Configurable: Custom allocators, null-pointer policies
• Zero dependencies: Just standard C library

Quick Start

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1. Include the header and declare your vector type:

/* my_vector.h */
#include "vector.h"
VECTOR_DECLARE(MyVector, my_vector, float)

2. Define the implementation (usually in a .c file):

#include "my_vector.h"
VECTOR_DEFINE(MyVector, my_vector, float)

3. Use it:

MyVector v = {0};
my_vector_push(&v, 3.14f);
my_vector_push(&v, 2.71f);

/* Fast iteration */
for (float *f = v.begin; f != v.end; f++) {
	printf("%.2f ", *f);
}

my_vector_free(&v);

Alternatively, if you plan to use your vector within a single file, you can do:

#include "vector.h"
VECTOR_DECLARE(MyVector, my_vector, float)
VECTOR_DEFINE(MyVector, my_vector, float)

API Overview

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• VECTOR_SIZE(vec) - Get element count
• VECTOR_CAPACITY(vec) - Get allocated capacity
• vector_push(vec, value) - Append element (O(1) amortized)
• vector_pop(vec) - Remove and return last element
• vector_get(vec, idx) / vector_set(vec, idx, value) - Random access
• vector_insert(vec, idx, value) / vector_delete(vec, idx) - Insert/remove at index
• vector_clear(vec) - Remove all elements
• vector_free(vec) - Deallocate memory

Configuration

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Define before including the library:

#define VECTOR_NO_PANIC_ON_NULL 1       /* Return silently on NULL instead of panic */
#define VECTOR_REALLOC my_realloc       /* Custom allocator */
#define VECTOR_FREE my_free             /* Custom deallocator */

Testing

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mkdir build
cmake -S . -B build/ -DCMAKE_BUILD_TYPE=Debug
cd build
make test

Tests cover normal operation, edge cases, out-of-memory conditions, and null pointer handling.

Why vector.h Over stb_ds.h?

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• Just as convenient: Both are single-header libraries
• Enhanced type safety: Unlike stb_ds.h, vector.h provides compile-time type checking
• Optimized iteration: vector.h uses the same iteration technique as std::vector, while stb_ds.h requires slower index calculations
• Safer memory management: vector.h avoids the undefined behavior that stb_ds.h uses to hide headers behind data
• Superior debugging experience: vector.h exposes its straightforward pointer-based internals, whereas stb_ds.h hides header data from debugging tools
• Robust error handling: vector.h fails fast with clear panic messages on out-of-bounds access, while stb_ds.h silently corrupts memory
• More permissive licensing: vector.h uses BSD0 (no attribution required, unlimited relicensing), which is less restrictive than stb_ds.h’s MIT and more universal than its public domain option since the concept doesn’t exist in some jurisdictions

Contribution

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Contributors and library hackers should work on vector.in.h instead of vector.h. It is a version of the library with hardcoded types and function names. To generate the final library from it, run libgen.py.

License

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This library is licensed under the BSD Zero license.