Introduction

libqrcode is C++23 header-only library for generating QR/Micro QR Codes.

Features include:

• Header-only library
• Completely constexpr
• Code is (unit-)tested with static_asserts during compile-time
• Utilizes standard library only
• Uses Ranges
• No C++ exceptions (however)

QR support

Supported:

• Versions: 1-40
• Error correction levels: L, M, Q, H
• Encodings: Numeric, alphanumeric, byte and kanji
• ECI mode (Enhanced channel interpretation)
• (Simple) Bit stream optimization

Not supported

• Structured append mode
• FNC1 mode

Micro QR support

Supported:

• Versions: M1-M4
• Error correction levels: L, M, Q (where possible)
• Encodings: Numeric, alphanumeric, byte and kanji encoding (where possible)

Usage

In your project, just in include the header qrcode/qrcode.h. Micro QR API is located within namespace micro_qr. QR API is located within namespace qr.

Simple example

#include <qrcode/qrcode.h>

int main()
{
    using namespace qrcode;

    auto qr_symbol = qr::make_symbol("Foo!", qr::error_correction::level_H);
    auto micro_qr_symbol = micro_qr::make_symbol("Bar!", micro_qr::error_correction::level_L);
}

ECI example

#include <qrcode/qrcode.h>

int main()
{
    using namespace qrcode;
    using namespace std::literals;

    auto symbol = qr::make_symbol(
        eci::view{eci::assignment_number{9}, "\xC1\xC2\xC3\xC4\xC5"sv}, 
        qr::error_correction::level_H);
}

Accessing modules

#include <qrcode/qrcode.h>
#include <iostream>

int main()
{
    using namespace qrcode;
    using namespace std::literals;
    
    auto symbol = qr::make_symbol("Hello World!"sv, qr::error_correction::level_L).value();

    auto count = 0;
    for (auto i : views::horizontal(symbol))
    {
        std::cout << (i ? '#' : ' ');
        ++count;
        if (count % width(symbol) == 0)
            std::cout << '\n';
    }
}

Requirements

• C++ compiler and standard library
• Supported:
  • gcc13 and libstdc++-13-dev
  • clang15 and libstdc++-13-dev
  • msvc: Visual Studio 2022 17.14.9
  • macos: AppleClang 16.0.0

How to build

• Since the library is header-only, building is actually not necessary.
• Just place the include folder of this project into your header search path.
• However, if you'd like to run the tests, please select the top-level of the project in order to run CMake.

How to run the tests

If you would like to run the tests, one has to add the following CMake flag: -DQRCODE_TESTS_ENABLED:BOOL=True

CI builds

The CI pipeline consist of test builds and demo builds for GCC, Clang, AppleClang and MSVC. If and only if all builds were successful, the CI state is green.