Eukaryotes. Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles. Genetic material in eukaryotes is contained within a nucleus within the cell and DNA is organized into chromosomes. Eukaryotic organisms may be multicellular or single-celled organisms. All animals are eukaryotes. Other eukaryotes include plants, fungi, and protists. A typical eukaryotic cell might contain the following parts: plasma membrane; nucleolus
A unique_lock can be created without immediately locking, can unlock at any point in its existence, and can transfer ownership of the lock from one instance to another. So you always use lock_guard, unless you need the capabilities of unique_lock. A condition_variable needs a unique_lock.
Thread-Safety: Both instance variable and static variable need to be controlled when used in multi threaded environment. But in case of an instance variable it does not need protection unless it is explicitly shared between threads but in case of a static variable it is always shared by all the threads in the process.