/usr/include/ql/methods/finitedifferences/meshers/ is in libquantlib0-dev 1.4-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ql/methods/finitedifferences/meshers/all.hpp
/usr/include/ql/methods/finitedifferences/meshers/concentrating1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/exponentialjump1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdm1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmblackscholesmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmblackscholesmultistrikemesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmhestonvariancemesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmmeshercomposite.hpp
/usr/include/ql/methods/finitedifferences/meshers/fdmsimpleprocess1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/predefined1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/uniform1dmesher.hpp
/usr/include/ql/methods/finitedifferences/meshers/uniformgridmesher.hpp