Commit (almost) automatically generated with the following sed command:
sed -i -ne '1h;1!H;${g;s|\n[[:blank:]]*private:\n\([[:blank:]]*\)// silence MSVC warning C4512: assignment operator could not be generated\n\([[:blank:]]*\)\([^\n]\+\);\n|\n\1// silence MSVC warning C4512: assignment operator could not be generated\n\2BOOST_DELETED_FUNCTION(\3);\n|g;p}' $(git ls-files)
Then all files in the x3 subfolder were reverted to HEAD, and manually
updated to use " = delete" instead of BOOST_DELETED_FUNCTION.