LaunchDarkly monorepo for C++ SDKs.

This repository contains LaunchDarkly SDK packages which are written in C++. This includes shared libraries, used by SDKs and other tools, as well as SDKs.

Packages

Readme	issues	tests	docs	latest release
libs/client-sdk	C++ Client SDK			On Github
libs/server-sdk	C++ Server SDK			On Github
libs/server-sdk-redis-source	C++ Server SDK - Redis Source			On Github

Shared packages	issues	tests
libs/common	Common
libs/internal	Internal
libs/server-sent-events	Common Server-Sent-Events

Organization

Directory	Description
.github	Contains CI and release process workflows and actions.
examples	Contains examples (hello-world style).
contract-tests	Contains contract test service.
cmake	Contains cmake files for importing and configuring external libraries.
libs	Contains library implementations. This includes libraries shared within the project as well as SDK libraries like the client-sdk.
scripts	Contains scripts used in the release process.
vendor	Contains third party source which is directly integrated into the project. Generally third party source is included through CMake using FetchContent, but some libraries require modification specific to this repository.

Build Requirements

Dependencies

1. C++17 and above
2. CMake 3.19 or higher
3. Ninja (if using the included build scripts)
4. Boost version 1.81 or higher
5. OpenSSL

Additional dependencies are fetched via CMake. For details see the cmake folder.

GoogleTest is used for testing.

For information on integrating an SDK package please refer to the SDK specific README.

CMake Usage

Various CMake options are available to customize the client/server SDK builds.

Option	Description	Default	Requires
BUILD_TESTING	Coarse-grained switch; turn off to disable all testing and only build the SDK targets.	On	N/A
LD_BUILD_UNIT_TESTS	Whether C++ unit tests are built.	On	BUILD_TESTING; NOT LD_BUILD_SHARED_LIBS
LD_TESTING_SANITIZERS	Whether sanitizers should be enabled.	On	LD_BUILD_UNIT_TESTS
LD_BUILD_CONTRACT_TESTS	Whether the contract test service (used in CI) is built.	Off	BUILD_TESTING
LD_BUILD_EXAMPLES	Whether example apps (hello world) are built.	On	N/A
LD_BUILD_SHARED_LIBS	Whether the SDKs are built as static or shared libraries.	Off (static lib)	N/A
LD_DYNAMIC_LINK_BOOST	If building SDK as shared lib, whether to dynamically link Boost or not. Ensure that the shared boost libraries are present on the target system.	On (link boost dynamically when producing shared libs)	LD_BUILD_SHARED_LIBS
LD_DYNAMIC_LINK_OPENSSL	Whether OpenSSL is dynamically linked or not.	Off (static link)	N/A
LD_BUILD_REDIS_SUPPORT	Whether the server-side Redis Source is built or not.	Off	N/A

Note: if building the SDKs as shared libraries, then unit tests won't be able to link correctly since the SDK's C++ symbols aren't exposed. To run unit tests, build a static library.

Basic usage example:

mkdir -p build && cd build
cmake -G"Unix Makefiles" ..

Slightly more advanced example - build shared libraries, and don't build any of the testing components:

mkdir -p build  && cd build
cmake -G"Unix Makefiles" -DLD_BUILD_SHARED_LIBS=On -DBUILD_TESTING=Off ..

The example uses make, but you might instead use Ninja, MSVC, etc.

LaunchDarkly overview

LaunchDarkly is a feature management platform that serves trillions of feature flags daily to help teams build better software, faster. Get started using LaunchDarkly today!

Testing

We run integration tests for all our SDKs using a centralized test harness. This approach gives us the ability to test for consistency across SDKs. These tests cover each method in the SDK, and verify that event sending, flag evaluation, stream reconnection, and other aspects of the SDK all behave correctly.

Contributing

We encourage pull requests and other contributions from the community. Check out our contributing guidelines for instructions on how to contribute to this SDK.

About LaunchDarkly

• LaunchDarkly is a continuous delivery platform that provides feature flags as a service and allows developers to iterate quickly and safely. We allow you to easily flag your features and manage them from the LaunchDarkly dashboard. With LaunchDarkly, you can:
  • Roll out a new feature to a subset of your users (like a group of users who opt-in to a beta tester group), gathering feedback and bug reports from real-world use cases.
  • Gradually roll out a feature to an increasing percentage of users, and track the effect that the feature has on key metrics (for instance, how likely is a user to complete a purchase if they have feature A versus feature B?).
  • Turn off a feature that you realize is causing performance problems in production, without needing to re-deploy, or even restart the application with a changed configuration file.
  • Grant access to certain features based on user attributes, like payment plan (eg: users on the ‘gold’ plan get access to more features than users in the ‘silver’ plan). Disable parts of your application to facilitate maintenance, without taking everything offline.
• LaunchDarkly provides feature flag SDKs for a wide variety of languages and technologies. Read our documentation for a complete list.
• Explore LaunchDarkly
  • launchdarkly.com for more information
  • docs.launchdarkly.com for our documentation and SDK reference guides
  • apidocs.launchdarkly.com for our API documentation
  • blog.launchdarkly.com for the latest product updates