This section describes the Intel® Threading Building Blocks (Intel® TBB) namespace conventions.
Namespace tbb contains public identifiers defined by the library that you can reference in your program.
Namespace tbb::flow contains public identifiers defined by the library that you can reference in your program related to the flow graph feature. See Flow Graph for more information .
Namespaces of the form tbb::interfacex define public identifiers that the library injects into namespace tbb. The numeral x corresponds to an internal version number that serves to prevent accidental linkage of incompatible definitions. Your code should never directly reference namespaces prefixed with tbb::interfacex. Instead, reference names via namespace tbb.
For example the header tbb/concurrent_hash_map.h defines the template concurrent_hashmap<Key,T> as tbb::version4::concurrent_hashmap<Key,T> and employs a using directive to inject it into namespace tbb. Your source code should reference it as tbb::concurrent_hashmap<Key,T>.
Namespace tbb::internal serves a role similar to tbb::interfacex. It is retained for backwards compatibility with older versions of the library. Your code should never directly reference namespace tbb::internal. Indirect reference via a public typedef provided by the header files is permitted.
The library uses the namespace tbb::deprecated for deprecated identifiers that have different default meanings in namespace tbb. Compiling with TBB_DEPRECATED=1 causes such identifiers to replace their counterpart in namespace tbb.
The library uses the namespace tbb::strict_ppl for identifiers that are put in namespace Concurrency when tbb/compat/ppl.h is included.