/*!

@mainpage Discovery Engine API C++ Client Library

An idiomatic C++ client library for the

[Discovery Engine API][cloud-service-docs], a service that powers

high-quality content recommendations on your digital properties.

While this library is **GA**, please note that the Google Cloud C++ client libraries do **not** follow

[Semantic Versioning](https://semver.org/).

@tableofcontents{HTML:2}

## Quickstart

The following shows the code that you'll run in the

`google/cloud/discoveryengine/quickstart/` directory,

which should give you a taste of the Discovery Engine API C++ client library API.

@snippet quickstart.cc all

## Main classes

<!-- inject-client-list-start -->

This library offers multiple `*Client` classes, which are listed below. Each one

of these classes exposes all the RPCs for a service as member functions of the

class. This library groups multiple services because they are part of the same

product or are often used together. A typical example may be the administrative

and data plane operations for a single product.

The library also has other classes that provide helpers, configuration

parameters, and infrastructure to mock the `*Client` classes when testing your

application.

- [\c discoveryengine_v1::CompletionServiceClient](@ref google::cloud::discoveryengine_v1::CompletionServiceClient)

- [\c discoveryengine_v1::ControlServiceClient](@ref google::cloud::discoveryengine_v1::ControlServiceClient)

- [\c discoveryengine_v1::ConversationalSearchServiceClient](@ref google::cloud::discoveryengine_v1::ConversationalSearchServiceClient)

- [\c discoveryengine_v1::DataStoreServiceClient](@ref google::cloud::discoveryengine_v1::DataStoreServiceClient)

- [\c discoveryengine_v1::DocumentServiceClient](@ref google::cloud::discoveryengine_v1::DocumentServiceClient)

- [\c discoveryengine_v1::EngineServiceClient](@ref google::cloud::discoveryengine_v1::EngineServiceClient)

- [\c discoveryengine_v1::GroundedGenerationServiceClient](@ref google::cloud::discoveryengine_v1::GroundedGenerationServiceClient)

- [\c discoveryengine_v1::ProjectServiceClient](@ref google::cloud::discoveryengine_v1::ProjectServiceClient)

- [\c discoveryengine_v1::RankServiceClient](@ref google::cloud::discoveryengine_v1::RankServiceClient)

- [\c discoveryengine_v1::RecommendationServiceClient](@ref google::cloud::discoveryengine_v1::RecommendationServiceClient)

- [\c discoveryengine_v1::SchemaServiceClient](@ref google::cloud::discoveryengine_v1::SchemaServiceClient)

- [\c discoveryengine_v1::SearchServiceClient](@ref google::cloud::discoveryengine_v1::SearchServiceClient)

- [\c discoveryengine_v1::SiteSearchEngineServiceClient](@ref google::cloud::discoveryengine_v1::SiteSearchEngineServiceClient)

- [\c discoveryengine_v1::UserEventServiceClient](@ref google::cloud::discoveryengine_v1::UserEventServiceClient)

<!-- inject-client-list-end -->

## More Information

- @ref common-error-handling - describes how the library reports errors.

- @ref discoveryengine-override-endpoint - describes how to override the default

endpoint.

- @ref discoveryengine-override-authentication - describes how to change the

authentication credentials used by the library.

- @ref discoveryengine-override-retry - describes how to change the default retry

policies.

- @ref discoveryengine-env - describes environment variables that can configure the

behavior of the library.

[cloud-service-docs]: https://cloud.google.com/discovery-engine

*/