template<typename_WordT=unsignedlonglong,typename_Alloc=std::allocator<_WordT>>
class std::tr2::dynamic_bitset< _WordT, _Alloc >::reference"This encapsulates the concept of a single
bit. An instance of this class is a proxy for an actual bit; this way the individual bit operations are
done as faster word-size bitwise instructions.
Most users will never need to use this class directly; conversions to and from bool are automatic and
should be transparent. Overloaded operators help to preserve the illusion.
(On a typical system, this 'bit %reference' is 64 times the size of an actual bit. Ha.)