Function foreach

src/slave/slave.cpp:496–500

Ensure disk `source`s are accessible.

  // Ensure disk `source`s are accessible.
  foreach (
      const Resource& resource,
      resources->filter([](const Resource& _resource) {
        return _resource.has_disk() && _resource.disk().has_source();
      })) {
    const Resource::DiskInfo::Source& source = resource.disk().source();
    switch (source.type()) {
      case Resource::DiskInfo::Source::PATH: {