delegate all comparison methods

[goretkin]

As pointed out in JuliaIntervals/IntervalArithmetic.jl#237 (comment)

the assumption at

Unitful.jl/src/quantities.jl

Line 324 in 47d131b

<=(x::AbstractQuantity, y::AbstractQuantity) = <(x,y) || x==y

<=(x::AbstractQuantity, y::AbstractQuantity) = <(x,y) || x==y

might not hold. Take for instance

using IntervalArithmetic: IntervalArithmetic, interval
using Unitful: Unitful, m

a = interval(0, 0)
b = interval(0, 1)
@assert a <= b
@assert a*m <= b*m  # assertion failure here

and the reason why is:

julia> a <= b
true

julia> a < b
false

julia> a == b
false

It seems worthwhile to delegate all comparison methods, not only isless and <, at

Unitful.jl/src/quantities.jl

Lines 263 to 275 in 47d131b

	for (i,j) in zip((:<, :isless), (:_lt, :_isless))
	@eval ($i)(x::AbstractQuantity, y::AbstractQuantity) = ($j)(x,y)
	@eval ($i)(x::AbstractQuantity, y::Number) = ($i)(promote(x,y)...)
	@eval ($i)(x::Number, y::AbstractQuantity) = ($i)(promote(x,y)...)
	# promotion might not yield Quantity types
	@eval @inline ($j)(x::AbstractQuantity{T1}, y::AbstractQuantity{T2}) where {T1,T2} = ($i)(promote(x,y)...)
	# If it does yield Quantity types, we'll get back here,
	# since at least the numeric part can be promoted.
	@eval @inline ($j)(x::AbstractQuantity{T,D,U}, y::AbstractQuantity{T,D,U}) where {T,D,U} = ($i)(x.val,y.val)
	@eval @inline ($j)(x::AbstractQuantity{T,D,U1}, y::AbstractQuantity{T,D,U2}) where {T,D,U1,U2} = ($i)(promote(x,y)...)
	@eval @inline ($j)(x::AbstractQuantity{T,D1,U1}, y::AbstractQuantity{T,D2,U2}) where {T,D1,D2,U1,U2} = throw(DimensionError(x,y))
	end