No-UCRT

A C++ library for Windows x64 that removes all CRT dependencies.

Feel free to contribute !

Features

Memory

• Custom Pool Allocator: set to 2 MB (change as prefered)
• Heap: wrapper for operator new/delete & malloc/free
• Direct Syscall: extracts SSNs from ntdll stubs at runtime for NtDelayExecution and NtYieldExecution

CRT

• vector: growable, push_back, erase & copy/move
• array, span: fixed size container and non-owning view
• string: append, substr, find, starts_with & ends_with
• string_view: non owning string view
• optional: holds a value or nothing, with nullopt or empty
• variant: tagged union, type safe get
• function: type erased callable with small object optimization
• hash: FNV-1a 64-bit for int, uint, long long, pointer & string
• unordered_map: hash map, insert, find, contains, erase & operator[]
• addressof: returns the actual address of an object
• sort, find, find_if, min, max & clamp: algorithm helpers
• sqrt, sin, cos, tan, atan2, pow, abs, isfinite: math
• printf: via WriteConsoleA output, %d %u %x %X %p %s %c %f %ll %z
• mutex, lock_guard: basic mutual exclusion and scoped locking
• once_flag, call_once: https://en.cppreference.com/cpp/thread/call_once
• this_thread::yield: calls NtYieldExecution
• this_thread::sleep_for: calls NtDelayExecution
• chrono: nanoseconds, microseconds, milliseconds, seconds, minutes & hours

Example

#define NOMINMAX
#include <windows.h>
#include "memory/heap/heap.h"
#include "syscall/syscall.h"
#include "crt/std.h"

int main()
{
    if (!NoUCRT::Initialize()) {
        // handle

        return false;
    }

    std::vector<int> vector;
    vector.push_back(1);
    vector.push_back(2);

    std::string string = "hello";
    string += " world";

    std::printf("vec[0]=%d str=%s sqrt2=%.4f\n", vector[0], string.c_str(), std::sqrt(2.0));
    return 0;
}

Building

To linker flags add: /NODEFAULTLIB to ofc exclude msvc's libs

Compile Flags

--target=x86_64-pc-windows-msvc
-x
c++
-Ivendor/no-ucrt
-std=c++23
-DWIN32_LEAN_AND_MEAN
-D_CRT_SECURE_NO_WARNINGS
-D_NO_CRT_STDIO_INLINE
-DNOMINMAX
-D_CSTDLIB_

Notes

• printf outputs to stdout via WriteConsoleA.
• Its suggested to implement your own pool allocator

Credits

https://github.com/mludvig/mini-printf