How do I change the C++ version supported by a project?

Question

How do I modify the C++ version? What are the C++ standards supported by the system?

Answer

libc++ version
HarmonyOS 3.0 supports libc++ with Clang/LLVM 10.0.1.

HarmonyOS 3.2 supports libc++ with Clang/LLVM 12.0.1.

HarmonyOS NEXT Developer Preview0 supports libc++ with Clang/LLVM 15.0.4.
Supported C++ capabilities
The C++11 and C++14 standards are fully supported, and the C++17 and C++20 standards are on the way.
Version modification
The default C++ version of the SDK is 14. To modify the version, use either of the following methods:
- Modify the version information in the CMakelists.txt file.
  set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})
  
  # Add the following line:
  
  set(CMAKE_CXX_STANDARD 17)# Set the C++ standard to 17.
- Add "cppFlags": "--std=c++17" to the build-profile.json5 file of the module.
```
"buildOption": {
  "externalNativeOptions": {
    "path": "./src/main/cpp/CMakeLists.txt",
    "arguments": "",
    // Modify the following line
    "cppFlags": "--std=c++17"
  },
},
```