Are there any instruction or sample code to write import func(x) in C(++)?

[Tatsuro M. <tma...@ya...>]

Hello

Prof. Takeno introduced a new feature 'import' on the gnuplot threads in Japan

On the ChangeLog, 2014-02-27, I have found the description.

I have read 'help import' and explanation for 'import' for gnuplot.pdf  created from the recent cvs source.

However I cannot find out how to prepare the C or C++ codes.
Are there any instruction or sample  code to write import func(x) in C(++)?

Regards

Tatsuro