bool ternary::encode(const int_vector &v, int_vector &z){
z.setIntWidth( v.getIntWidth() );
size_t z_bit_size = 0;
for(typename int_vector::const_iterator it = v.begin(), end = v.end(); it != end; ++it){
z_bit_size += encoding_length(*it);
}
z.bit_resize( z_bit_size ); // Initial size of z
if( z_bit_size & 0x3F ){ // if z_bit_size % 64 != 0
*(z.m_data + (z_bit_size>>6)) = 0; // initialize last word
}
