Numerics library

The Arm^® C++ standard library implementation has the following features:

• For the constructor std::random_device, implementation limitations prevent generating nondeterministic random numbers. The implementation uses a pseudo-random number engine.
• The default constructor of std::random_device uses the token "pseudorandom".
• The only valid value of the parameter token of the std::random_device constructor explicit random_device(const string& token) is "pseudorandom".
• If there is a failure, the type of exceptions that std::random_device constructors throw is std::system_error.
• The member function result_type operator()() of std::random_device never fails.