This function is used in the
itp package to
create external pointers to the C++ functions used as examples to
illustrate the use of the function
itp. These pointers are
passed as the argument
itp. To create their own
examples the user will need to create their own C++ function(s) and a
function that is similar to
A string indicating the C++ function required.
The external pointer.
The example C++ functions available in
xptr_eval for calling a C++ function using an