Support for std::unordered_map

[alhirzel]

What would the process look like for adding support for std::unordered_map? I think it could map nicely onto a Dict.

[barche]

You need to add a new type to the libcxxwrap-julia STL library, here is an example diff of what was needed for std::valarray: https://github.com/JuliaInterop/libcxxwrap-julia/commit/47a760fab8a03551fb06c785a0d98280e89a151f

And then the Julia interface is best implemented on the Julia side, mainly in the StdLib.jl file: https://github.com/JuliaInterop/CxxWrap.jl/commit/2e522bb9826fd41243f4e2862395dfff288b9bdb

[eschnett]

See also https://github.com/JuliaInterop/libcxxwrap-julia/issues/88.