Can't load Measurement quantities with JLD.jl

[Mason Protter]

Here's a MWE:

julia> using Measurements, JLD

julia> x = 1 ± 0.1
1.0 ± 0.1

julia> @save "x.jld" x

julia> exit()

~$ julia

julia> using Measurements, JLD

julia> @load "x.jld" x
ERROR: MethodError: no method matching setindex!(::Measurements.Derivatives{Float64}, ::Float64, ::Tuple{Float64,Float64,UInt64})
Closest candidates are:
  setindex!(::AbstractDict, ::Any, ::Any, ::Any, ::Any...) at abstractdict.jl:477
Stacktrace:
 [1] convert(::Type{Measurements.Derivatives{Float64}}, ::JLD.AssociativeWrapper{Tuple{Float64,Float64,UInt64},Float64,Measurements.Derivatives{Float64}}) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:809
 [2] readas(::JLD.AssociativeWrapper{Tuple{Float64,Float64,UInt64},Float64,Measurements.Derivatives{Float64}}) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:792
 [3] read_scalar(::JLD.JldDataset, ::HDF5.HDF5Datatype, ::Type) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:398
 [4] read(::JLD.JldDataset) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:370
 [5] read_ref(::JLD.JldFile, ::HDF5.HDF5ReferenceObj) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:502
 [6] jlconvert(::Type{Measurement{Float64}}, ::JLD.JldFile, ::Ptr{UInt8}) at /Users/mason/.julia/packages/JLD/1BoSz/src/jld_types.jl:434
 [7] read_scalar(::JLD.JldDataset, ::HDF5.HDF5Datatype, ::Type) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:398
 [8] read(::JLD.JldDataset) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:370
 [9] read(::JLD.JldFile, ::String) at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:346
 [10] top-level scope at /Users/mason/.julia/packages/JLD/1BoSz/src/JLD.jl:1196

[Mosè Giordano]

Measurements.Derivatives is an immutable dictionary, so setindex! doesn't make much sense. Any idea of what would make it possible to make this work? I never played much with JLD.

[Mosè Giordano]

Note that now Measurement objects can be serialised with JLD2: JuliaIO/JLD2.jl#189

[Mason Protter]

Nice!