lst-0004-book.cpp
// https://godbolt.org/z/Moe5M7sK8
Data const * data = new Data(5);
data->value = 7; // this const protects Data
data = new Data(6); // reassigning pointer is okay
Data * const more = new Data(8);
more->value = 9; // now okay
more = new Data(10); // reference is protected