Yucky code dump

Mildly yucky

Unnecessary str::string instantiations

Getting substrings

Don't do this: https://stackoverflow.com/a/55210196 (applies to the last revision from 2019)

auto str = std::string(input.begin() + input.find(' '), input.end());

Do this:

auto str = std::string_view(input.begin() + input.find(' '), input.end());

That neatly avoids allocating space for the substring and then copying the substring there.