I have a project that written in C++17, let's name it A. It's using some C++17 specific features like std::optional, inline variables and etc...
My question is can I use that project as a third party library in a C++14 project (let's say project B) by compiling project A as static library and then use it in project B ? Even though headers of project A still has some functions and variables that declared using C++17 features ?