when install codeblocks, there should be an option to install c++11 / c++14 / c++17 / c++20 / c++23 at once.
the disk storage is no more a problem, but, if a program needed to run under different c++, there is a need to change definitions.
every c++ version can have it's own subdirectory.
for each project in the left side, an option can be added to move it from c++ to another.