https://www.boost.org/doc/libs/1_52_0/doc/html/boost/units/add_typeof_helpe_id1897777.html
Struct template add_typeof_helperquantity unit Dim, System , X , quantity unit Dim, System...
dim systemstructtemplateaddtypeof
https://www.boost.org/doc/libs/develop/doc/html/doxygen/units_reference/structboost_1_1units_1_1power__typeof__helper_3_01unit_3_01Dim_00_01System_01_4_00_01static__rational_3_01N_00_01D_01_4_01_4.html
Struct template power_typeof_helperunit Dim, System , static_rational N, D
dim systemstructtemplatepowertypeof
https://www.boost.org/doc/libs/1_52_0/doc/html/boost/units/power_typeof_hel_id1899817.html
Struct template power_typeof_helperunit Dim, System , static_rational N, D
dim systemstructtemplatepowertypeof
https://www.boost.org/doc/libs/1_52_0/doc/html/boost/units/root_typeof_help_id1899921.html
Struct template root_typeof_helperunit Dim, System , static_rational N, D
dim systemstructtemplateroottypeof