OpenCSTL is a single-header, C-native container library that brings the
feel of C++ STL into pure C. push_back, insert,
begin/end, rbegin/rend,
first/second, even [] access — without
templates, codegen, or per-type macro rituals.
#include "opencstl.h" int main(void) { VECTOR(int) = new_vector(int); push_back(v, 10); push_back(v, 20); push_back(v, 30); // STL-like iterators… for (int* it = begin(v); it != end(v); it = next(v, it)) printf("%d\n", *it); // …or just index it like an array. for (size_t i = 0; i < size(v); i++) printf("v[%zu] = %d\n", i, v[i]); }
Most C container libraries give you the data structures. OpenCSTL gives you the sensation of writing STL — in code that still compiles cleanly under C99 on tcc, NVCC, Pelles C, and every mainstream compiler.
See the comparison →OpenCSTL lets C programmers use containers with familiar C++ STL semantics — push_back, insert, begin/end, rbegin/rend, first/second, even [ ] access where applicable — without templates, code generation, or per-type macro boilerplate.
The differences with STC, M*LIB, and CC are not cosmetic. They change what writing a C file feels like.
push_back, insert, begin/end,
rbegin/rend, next/prev, first/second
— they all mean what a C++ programmer expects them to mean.
push_back(v, 42); insert(m, 1, "one"); rbegin(m); it->first;
Drop opencstl.h in. Done. No
#define TYPE int ritual, no template instantiation
file, no per-type forward declarations cluttering the top of
your translation unit.
#include "opencstl.h" // that's it.
push_back works on vector, list,
deque. insert works on every container that
can take an insert. No prefix soup. No name suffixes.
push_back(vec, x); push_back(list, y); push_back(deq, z);
qsort and bsearch.
v[i] and q[i] are real array accesses —
vector and deque both subscript like
plain C arrays. That means the C standard library still works —
pass containers to qsort, bsearch,
anywhere that takes a pointer and a size.
qsort(v, size(v), sizeof(char*), LESS(char*));
The C generic-container space has good libraries. OpenCSTL is the only one that ticks every box on this list — and that combination is what reproduces the C++ STL feel.
The set leans on what C programmers use day to day — sequence,
associative, and hashed — plus the adaptor trio
(stack, queue, priority_queue).
v[i] accessq[i] accessOpenCSTL is not just another C container library. It is a single-header, C-native STL-like library that lets C programmers write containers with familiar C++ STL semantics — without templates, code generation, or per-type macro boilerplate.
OpenCSTL은 단순한 C 컨테이너 라이브러리가 아닙니다.
push_back, insert, begin/end,
rbegin/rend, first/second, [ ]
접근까지 C++ STL의 사용감을 C 코드 안에서 그대로 구현한
single-header C-native STL-like library입니다.
No build system to configure, no submodule to wire up, no per-type template instantiation file to maintain. Curl it, include it, ship.
$ curl -LO https://raw.githubusercontent.com/springkim/OpenCSTL/refs/heads/master/opencstl.h $ gcc main.c -p main $ ./main
From MSVC 2026 to tcc, from Windows to
Linux to macOS — OpenCSTL builds cleanly across the C ecosystem
you actually ship in. Every C standard from
C89 through C23 is supported, and the
single header even compiles on C++ compilers.
| Compiler | Windows | macOS | Linux |
|---|---|---|---|
| MSVC cl | ✓ | ✗ | ✗ |
| GNU / MinGW64 gcc | ✓ | ✓ | ✓ |
| LLVM clang | ✓ | ✓ | ✓ |
| Intel icx-cc | ✓ | ✗ | ✓ |
| Tiny C Compiler tcc | ✓ | ✓ | ✓ |
| zig cc | ✓ | ✓ | ✓ |
| Pelles C pocc | ✓ | ✗ | ✗ |
| NVCC nvcc | ✓ | ✓ | ✗ |
| C++Builder bcc64x | ✓ | ✗ | ✗ |