compat.gmp

// compat.gmp `gmpxx` feature: the C++ bindings compile against the consumer's
// own toolchain and link.
//
// The stream operators are the load-bearing part. Everything else in gmpxx.h is
// inline in the header, so a member that only did arithmetic would link with
// the feature TURNED OFF and prove nothing. `os << mpz_class` resolves to
// __gmp_ostream_operator, which lives in cxx/osmpz.cc — one of the eleven
// sources the feature gates.
//
// It is also the one place where "compiled by the consumer's toolchain" is
// actually tested: those symbols carry std::ostream / std::string in their
// mangled names, so a prebuilt libgmpxx would resolve on libstdc++ and fail on
// libc++.

#include <gmpxx.h>

#include <cstdio>
#include <iostream>
#include <sstream>
#include <string>

namespace {
// …