#include <boost/bit_logic/assign.hpp> 
  bit_concat_functor concat ( BitType bit_store ) ; 

The concat function returns a functor object whose operator() member functions are used to concatonate bits. The bit_concat_functor is convertible to a bit_vector.

For example:

  uint16_t top = 0xdead ; 
  bit_array<4> middle = "1001" ;
  bit_array<8> bottom = "00100001" ; 	
  cout << hex << concat ( top )( middle )( bottom ) << endl ;

This code will output:

  dead921

This code can throw no exception.