CBOR C++ Library

cbor is a C++20 library designed to encode and decode CBOR (Concise Binary Object Representation) sequences. The library optionally supports reflection via Boost PFR.

Usage

The recommended way to include this library in your project is to use the CMake's FetchContent functionality, for example:

cmake_minimum_required(VERSION 3.16)
project(cbor_example)

set(CMAKE_CXX_STANDARD 20)

include(FetchContent)

# Fetch the CBOR library
FetchContent_Declare(
    cbor
    GIT_REPOSITORY https://github.com/yowidin/cbor
    GIT_TAG master
)
FetchContent_MakeAvailable(cbor)

# Also fetch the Simple Hex Printer Library for easier printing (not required).
FetchContent_Declare(
    shp
    GIT_REPOSITORY https://github.com/yowidin/simple-hex-printer
    GIT_TAG master
)
FetchContent_MakeAvailable(shp)

add_executable(example main.cpp)
target_link_libraries(example PRIVATE CBOR::library SimpleHexPrinter::library)

And then in a C++ file:

#include <cbor/cbor.h>
#include <shp/shp.h>

#include <format>
#include <iostream>
#include <vector>

enum class kind {
   cat = 0,
   dog,
   hamster,
   fish,
};

struct pet {
   std::string name{};
   kind kind{};
};

// Plain (w/o the type ID) structures have to be whitelisted
[[maybe_unused]] consteval void enable_cbor_encoding(pet);

std::string_view to_string(kind k) {
   switch (k) {
      case kind::cat: return "cat";
      case kind::dog: return "dog";
      case kind::hamster: return "hamster";
      case kind::fish: return "fish";
      default: return "alien";
   }
}

std::string to_string(const pet &p) {
   return std::format("Pet {} named {}", to_string(p.kind), p.name);
}

int main(int, char **) {
   std::cout << "Simple CBOR example.\n";
   std::cout << "   Use https://cbor.me/ to check the serialization.\n\n";

   // Encoding
   std::vector<std::byte> target{};
   cbor::dynamic_buffer out{target};

   const std::vector<pet> input{
      {.name = "Bailey", .kind = kind::dog},
      {.name = "Whiskers", .kind = kind::cat},
      {.name = "Sushi", .kind = kind::fish},
      {.name = "Budweiser", .kind = kind::hamster},
   };

   if (auto res = cbor::encode(out, input)) {
      std::cerr << std::format("Encoding error: {}\n", res.message());
   }

   std::cout << "Encoded:\n" << shp::hex(target) << "\n\n";

   // Decoding
   cbor::read_buffer buf{{target}};
   std::vector<pet> decoded{};

   if (auto res = cbor::decode(buf, decoded)) {
      std::cerr << std::format("Decoding error: {}\n", res.message());
   }

   std::cout << "Decoded:\n";
   for (const auto &p : decoded) {
      std::cout << std::format("- {}\n", to_string(p));
   }

   return 0;
}

Output:

Simple CBOR example.
   Use https://cbor.me/ to check the serialization.

Encoded:
0x00: 84 82 66 42 61 69 6C 65 79 01 82 68 57 68 69 73  ..fBailey..hWhis
0x10: 6B 65 72 73 00 82 65 53 75 73 68 69 03 82 69 42  kers..eSushi..iB
0x20: 75 64 77 65 69 73 65 72 02                       udweiser.

Decoded:
- Pet dog named Bailey
- Pet cat named Whiskers
- Pet fish named Sushi
- Pet hamster named Budweiser

For more examples, please refer to the example directory in the repository.

License

This project is licensed under the MIT License. See the LICENSE.txt file for details.

Feedback

Feel free to provide feedback or ask questions by opening an issue on the repository.