libstdc++
Namespace List
Here is a list of all documented namespaces with brief descriptions:
__gnu_cxxGNU extensions for public use
__gnu_cxx::__detailImplementation details not part of the namespace __gnu_cxx interface
__gnu_cxx::typelistGNU typelist extensions for public compile-time use
__gnu_debugGNU debug classes for public use
__gnu_internalGNU implemenation details, not for public use or export. Used only when anonymous namespaces cannot be substituted
__gnu_parallelGNU parallel code for public use
__gnu_pbdsGNU extensions for policy-based data structures for public use
__gnu_profileGNU profile code for public use
__gnu_sequentialGNU sequential classes for public use
abiThe cross-vendor C++ Application Binary Interface. A namespace alias to __cxxabiv1, but user programs should use the alias 'abi'
stdISO C++ entities toplevel namespace is std
std::__debugGNU debug code, replaces standard behavior with debug behavior
std::__detailImplementation details not part of the namespace std interface
std::__parallelGNU parallel code, replaces standard behavior with parallel behavior
std::__profileGNU profile code, replaces standard behavior with profile behavior
std::chronoISO C++ 0x entities sub namespace for time and date
std::decimalISO/IEC TR 24733 Decimal floating-point arithmetic
std::placeholdersISO C++11 entities sub-namespace for functional.

std::regex_constantsISO C++-0x entities sub namespace for regex
std::rel_opsThe generated relational operators are sequestered here
std::this_threadISO C++ 0x entities sub namespace for thread. 30.2.2 Namespace this_thread
std::tr1ISO C++ TR1 entities toplevel namespace is std::tr1
std::tr1::__detailImplementation details not part of the namespace std::tr1 interface
std::tr2ISO C++ TR2 entities toplevel namespace is std::tr2
std::tr2::__detailImplementation details not part of the namespace std::tr2 interface