Conversions from primitive C types to Lpp objects is done with the L constructor and back to primitive C types is done with the xL converter, where x designates a primitive C type.
Implicit constructors were avoided in Lpp for good reasons. One major
reason is that it eliminated overloaded name conflicts with other C++
libraries. Another reason is that 0 as nil and 0 as integer is
problematical. This may seem like a real inelegancy. For example the
programmer has to specify list(L(55), L("string"), L(fun))
instead of simply list(55, "string", fun), but as it turns out
this is not much of a problem in actual programming practice. Also,
provided functions like listSEM("one", "two", "three", EM) for
long homogeneous lists of like objects helps.
The name of the L constructor can be redefined per compilation
unit, See Redefining Predefined Names.