unistd::statOptional() implementation.
cgroup::{HierarchyInfo,SystemInfo} implementation.
HierarchyInfo, SystemInfo and errors refactoring.
SystemInfo::instance() bug fix.
ProcessHierarchyInfo and ProcessInfo implementation.
FileFormatError and FileLineFormatError implementation.
ProcPidCgroup implementation.
SystemInfo and ProcessInfo refactoring.
detail::{I,O}StreamableWrapper implementation.
Headers inclusion bug fixes.
cgroup::swap(ProcessInfo, ProcessInfo) bug fix.
cgroup::ControlGroup refactoring.
cgroup::SingleControlGroup partial implementation.
cgroup::Subsystem refactoring.
cgroup::ControlGroup thread-safety description.
cgroup::ControlGroup naming fix.
cgroup::ControlGroup {attach,create}Child() and parent() implementation.
cgroup::SingleControlGroup refactoring.
cgroup::Error::controlGroupPath declaration.
cgroup::SingleControlGroup: hierarchy traversal partial implementation.

~SingleControlGroup(), attachChild(), createChild(), root() and attach() implementation.
attachDirectChild() and createDirectChild() declaration.