adding methods to `promote_type` is not allowed

[nsajko]

You probably meant to define promote_rule mehods instead:

BitBasis.jl/src/longlonguint.jl

Lines 26 to 27 in 7380c63

	Base.promote_type(::Type{LongLongUInt{C}}, ::Type{Int}) where {C} = LongLongUInt{C}
	Base.promote_type(::Type{LongLongUInt{C}}, ::Type{UInt}) where {C} = LongLongUInt{C}

[GiggleLiu]

Indeed. Thank you for pointing this out. I have fixed it in the PR above.