gRPC Core with C++ standard library Announcement

[Esun Kim]

TL;DR Starting from gRPC 1.24, gRPC Core will start to have a dependency against the C++ standard library (e.g. libstdc++.so or libc++.so). As a result, all wrapped gRPC libraries based on gRPC Core (C++, C#,  Node.js, Objective-C, PHP, Python, and Ruby) have new dependency against the C++ standard library, too. 

To have better productivity in writing gRPC Core, gRPC Core will start using C++ standard library from gRPC 1.24. Previously, gRPC Core didn't have a dependency against the C++ standard library for better portability, but since all of our supported platforms now provide the C++ standard library, this change is considered safe. So we decide to add this dependency to gRPC Core. As a result, all wrapped gRPC libraries based on this will have C++ stdlib dependency, too.

For gRPC Users:

We expect that most users will not see any problem with this change, because most platforms are bundled with the C++ standard library. To keep it gRPC portable as much as possible, gRPC Core will be restricted to use C++ standard library features available in GLIBCXX_3.4.9, which was released in 2007.

Change for individual platforms:

• Linux: C++ library will be dynamically linked. If the system doesn’t have C++ standard library (e.g. Alpine Linux), you may need to install it.

• Windows: C++ library will be statically linked so it should be fine.

• MacOS, iOS, and Android: C++ library will be dynamically linked but these platforms have pre-installed C++ library so it should be fine.

Change for individual languages:

• C++, Node.js, Objective-C, and Python: These gRPC libraries already have been linked to C++ standard library before this change, so users may not see any change.

• C#, PHP, and Ruby: These gRPC libraries will start to be linked to C++ standard library with this change, so users may see changes.

For gRPC Contributors:

We will use only limited features of C++ standard library until gRPC 1.24 has successfully deployed: std::map and pure virtual functions. This will enable us to roll this change back if there is a serious problem on a particular language or platform. Once gRPC 1.24 is proven safe to use, we will then allow use of the full C++11 standard library. 

* Related proposal: L59 - Allow C++ standard library in gRPC Core Library (PR, file)