This example will not compile with Pike versions 7.4.20 unless you first
patch the Pike sources. The problem is for line 91 of Pike's "stralloc.h"
(usually installed as /usr/local/pike/7.4.10/include/pike/stralloc.h). That
line reads:

    tmp.ptr=ptr;

but should be patched to read:

    tmp.ptr=(p_wchar0 *) ptr;

This bug has been reported to the Pike developers.