New issue on `get__()` versus `get()`

[eddelbuettel]

This came up in the reverse depends check for #1482, but reproduces locally for me. Package RestRserve has a .hasAttribute() check, and that fails on

ccache g++ -I"/usr/share/R/include" -DNDEBUG  -I'/usr/local/lib/R/site-library/Rcpp/include'    -DRCPP_NO_MODULES -fpic  -g0 -O3 -Wall -pipe -Wno-unused  -fext-numeric-literals -DBOOST_NO_AUTO_PTR    -c format_\
headers.cpp -o format_headers.o
In file included from /usr/local/lib/R/site-library/Rcpp/include/Rcpp/proxy/proxy.h:24,
                 from /usr/local/lib/R/site-library/Rcpp/include/RcppCommon.h:132,
                 from /usr/local/lib/R/site-library/Rcpp/include/Rcpp.h:27,
                 from format_headers.cpp:3:
/usr/local/lib/R/site-library/Rcpp/include/Rcpp/proxy/AttributeProxy.h: In instantiation of ‘bool Rcpp::AttributeProxyPolicy<CLASS>::hasAttribute(const std::string&) const [with CLASS = Rcpp::ListOf<Rcpp::Vecto\
r<16> >; std::string = std::__cxx11::basic_string<char>]’:
format_headers.cpp:12:22:   required from here
   12 |   if (!x.hasAttribute("names")) {
      |        ~~~~~~~~~~~~~~^~~~~~~~~
/usr/local/lib/R/site-library/Rcpp/include/Rcpp/proxy/AttributeProxy.h:100:61: error: ‘const class Rcpp::ListOf<Rcpp::Vector<16> >’ has no member named ‘get__’; did you mean ‘get’?
  100 |         return R_hasAttrib(static_cast<const CLASS&>(*this).get__(), Rf_install(attr.c_str()));
      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
      |                            get
make: *** [/usr/lib/R/etc/Makeconf:199: format_headers.o] Error 1
ERROR: compilation failed for package ‘RestRserve’

It does indeed go away if we replace get__() with get() here:

Rcpp/inst/include/Rcpp/proxy/AttributeProxy.h

Line 100 in 8d2f8f8

return R_hasAttrib(static_cast<const CLASS&>(*this).get__(), Rf_install(attr.c_str()));

but as even that file has another get__() I am wondering if we need a more general chase for it?