A compiling error is caused by "‘std::optional’ is only available from C++17 onwards".

[yiyuzhuang]

Problem:

When building the project, an error message is encountered: "‘std::optional’ is only available from C++17 onwards". This error occurs because the project uses the std::optional feature, which is available in C++17 and later versions, but the project is not configured to use C++17.

Solution:

To resolve this issue, set the C++ standard to C++17 in the project's CMakeLists.txt file by adding the following lines:

set(CMAKE_CXX_STANDARD 17) set(CMAKE_CXX_STANDARD_REQUIRED ON) set(CMAKE_CXX_EXTENSIONS OFF)

These lines configure the project to use C++17, make it a required standard, and disable compiler-specific extensions. After adding these lines to the CMakeLists.txt file, re-run the CMake command to configure the project. The project should now be compiled using C++17, and the error related to std::optional should be resolved.