Precision loss when adding a nested model

[hauke76]

Hi,

I stumbled over the issue that adding nested models results in a floating point precision loss. When adding a nested model, the _includeSDF is converted to a string through a call to Element::ToString. This ultimately calls Param::GetAsString() which uses the ParamStreamer to write data to a std::ostream. By injecting std::setprecision(std::numeric_limits<T>::max_digits10) in the output stream this precision loss can be prevented.

Kind regards,
Hauke

[hauke76]

I created a pull request for the master branch here: #314
I have a similar fix available for v6.x and it would be great if you could consider that as a merge request as well.

[EricCousineau-TRI]

Given merge of #314, closing this issue. Thanks!