Describe the feature and motivation

When building with -DCMAKE_CXX_STANDARD=20, there are many build warnings for both GCC and clang.

What we have to do are ...

• use constexpr instead of enum definition value
• cast to calicurate mixing different enums
• do not increment volatile variable
• remove unused variable
• use vector.reserve() instead of vector.resise() after vector.clear()

Additional context

No response