1 2# libc++ 3 4Currently, OpenHarmony uses the C++ standard library [(libc++)](https://libcxx.llvm.org/) of the LLVM project. 5 6## Version 7 8From OpenHarmony 3.0, libc++ uses Clang/LLVM 10.0.1. 9 10From OpenHarmony 3.2, libc++ is upgraded to Clang/LLVM 12.0.1. 11 12From OpenHarmony 4.0, libc++ is upgraded to Clang/LLVM 15.0.4. 13 14## Supported Capabilities 15 16The C++11 and C++14 standards are supported, and the C++17 and C++20 standards are on the way. For details about the standards supported by language features, see the corresponding Release Notes at [https://libcxx.llvm.org/](https://libcxx.llvm.org/). 17 18## ABI Compatibility 19In OpenHarmony, both the system library and application native library use the libc++. However, the two libc++ are different. The libc++ of the system library is updated with the image version, while the libc++ of the application native library is updated with the SDK version used for compilation. Both the libc++ libraries cross multiple major versions, which may cause Application Binary Interface (ABI) compatibility issues. To solve this problem, OpenHarmony differentiates the libc++ libraries as follows: 20 * System library: uses **libc++.so**, which is released with the system image. 21 * Application native library: uses **libc++_shared.so**, which is released with the application. 22 23The two libc++ libraries use different namespaces. **libc++_shared.so** uses **__n1** as the namespace for C++ symbols, and **libc++.so** uses **__h** as the namespace for C++ symbols. 24 25> **CAUTION** 26> 27> Currently, the Native API supports C only. The system library can use any programming language. 28 29<!--no_check-->