lvc

lvc is a set of C++ containers extracted form LLVM for an easier integration in external projects.

To avoid any potential conflit, the llvm namespace has been replaced by lvc.

Available containers

lvc::SmallVector: a std::vector like container with an inline small buffer to avoid dynamic allocations when a small number of elements is used.

More containers will be added over time or on request. Feel free to open a PR to add a new one.

Examples

SmallVector

#include <lvc/SmallVector.h>

// Take any SmallVector of ints no matter its inline buffer size
void addInt(lvc::SmallVectorImpl<int>& vec) {
    vec.push_back(42);
}

int main() {
    // reserve storage for two elements on the stack
    lvc::SmallVector<int, 2> vec;

    auto is_inline_buffer_used = [&v] {
        const void* vec_start = &v;
        constexpr auto vec_size = sizeof(v);
        const void* buffer_start = v.data();
        return (buffer_start > vec_start) && (buffer_start < vec_start + size);
    };

    addInt(vec);
    addInt(vec);

    // elements fit the inline buffer
    assert(is_inline_buffer_used());

    addInt(vec);

    // too many elements, buffer has to be heap allocated
    assert(!is_inline_buffer_used());
}

Installation

Unless tests are built, no external dependencies are required. The only tools you need to build lvc are:

CMake >= 3.14
A C++14 compatible compiler

From source

Download/clone this repo, then build and install it as usual with CMake, e.g:

git clone https://github.com/BenjaminNavarro/lvc.git
cd lvc
mkdir build
cd build
cmake ..
cmake --build . --target install --parallel

Then in your project's CMakeLists.txt simply do:

find_package(lvc)
target_link_libraries(my-app PRIVATE lvc::lvc)

Using Conan

Add https://bnavarro.jfrog.io/artifactory/api/conan/bnavarro to your remotes and declare a dependency to lvc (e.g lvc/11.1.0@bnavarro/stable).

You can of course download/clone the repo then run the usual conan install and conan create commands.

Using CPM.cmake

The project is FetchContent friendly so CPM.cmake can be used.

For instance in your CMakeLists.txt you could do:

include(cmake/CPM.cmake)
CPMAddPackage("gh:BenjaminNavarro/lvc@11.1.0")

Acknowledgements

The source code comes from the LLVM project and receives only minimal modifications: namespace changed to lvc and support files trimmed down to keep the number of included files low and the project small.

The initial project structure was generated by cmake-init.

Versioning

The project's is the LLVM's version where the containers were extracted from.

The patch version may differ if the project requires fixes or if new containers are added.

BenjaminNavarro / lvc

lvc