This directory contains an idiomatic C++ client library for interacting with Google Cloud Spanner, which is a fully managed, scalable, relational database service for regional and global application data.

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

• Windows, macOS, Linux
• C++14 (and higher) compilers (we test with GCC >= 7.3, Clang >= 6.0, and MSVC >= 2017)
• Environments with or without exceptions
• Bazel (>= 4.0) and CMake (>= 3.5) builds

• Official documentation about the Cloud Spanner service
• Reference doxygen documentation for each release of this client library
• Detailed header comments in our public .h files

The quickstart/ directory contains a minimal environment to get started using this client library in a larger project. The following "Hello World" program is used in this quickstart, and should give you a taste of this library.

#include "google/cloud/spanner/client.h"
#include <iostream>

int main(int argc, char* argv[]) {
  if (argc != 4) {
    std::cerr << "Usage: " << argv[0]
              << " project-id instance-id database-id\n";
    return 1;
  }

  namespace spanner = ::google::cloud::spanner;
  spanner::Client client(
      spanner::MakeConnection(spanner::Database(argv[1], argv[2], argv[3])));

  auto rows =
      client.ExecuteQuery(spanner::SqlStatement("SELECT 'Hello World'"));

  for (auto const& row : spanner::StreamOf<std::tuple<std::string>>(rows)) {
    if (!row) {
      std::cerr << row.status() << "\n";
      return 1;
    }
    std::cout << std::get<0>(*row) << "\n";
  }

  return 0;
}

• Packaging maintainers or developers who prefer to install the library in a fixed directory (such as /usr/local or /opt) should consult the packaging guide.
• Developers that prefer using a package manager such as vcpkg, Conda, or Conan should follow the instructions for their package manager.
• Developers wanting to use the libraries as part of a larger CMake or Bazel project should consult the quickstart guides for the library or libraries they want to use.
• Developers wanting to compile the library just to run some examples or tests should read the current document.
• Contributors and developers to google-cloud-cpp should consult the guide to set up a development workstation.

See CONTRIBUTING.md for details on how to contribute to this project, including how to build and test your changes as well as how to properly format your code.

Apache 2.0; see LICENSE for details.