ceph/src/boost/libs/dll/example/tutorial3/tutorial3.cpp

   1 // Copyright 2014 Renato Tegon Forti, Antony Polukhin.
   2 // Copyright Antony Polukhin, 2015-2022.
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt
   6 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #include "../b2_workarounds.hpp"
   9 //[callplugcpp_tutorial3
  10 #include <boost/dll/import.hpp> // for import_alias
  11 #include <boost/make_shared.hpp>
  12 #include <boost/function.hpp>
  13 #include <iostream>
  14 #include "../tutorial_common/my_plugin_api.hpp"
  15
  16 namespace dll = boost::dll;
  17
  18 std::size_t search_for_symbols(const std::vector<boost::dll::fs::path>& plugins) {
  19     std::size_t plugins_found = 0;
  20
  21     for (std::size_t i = 0; i < plugins.size(); ++i) {
  22         std::cout << "Loading plugin: " << plugins[i] << '\n';
  23         dll::shared_library lib(plugins[i], dll::load_mode::append_decorations);
  24         if (!lib.has("create_plugin")) {
  25             // no such symbol
  26             continue;
  27         }
  28
  29         // library has symbol, importing...
  30         typedef boost::shared_ptr<my_plugin_api> (pluginapi_create_t)();
  31         boost::function<pluginapi_create_t> creator
  32             = dll::import_alias<pluginapi_create_t>(boost::move(lib), "create_plugin");
  33
  34         std::cout << "Matching plugin name: " << creator()->name() << std::endl;
  35         ++ plugins_found;
  36     }
  37
  38     return plugins_found;
  39 }
  40
  41 //]
  42
  43 int main(int argc, char* argv[]) {
  44     BOOST_ASSERT(argc >= 3);
  45     std::vector<boost::dll::fs::path> plugins;
  46     plugins.reserve(argc - 1);
  47     for (int i = 1; i < argc; ++i) {
  48         if (b2_workarounds::is_shared_library(argv[i])) {
  49             plugins.push_back(argv[i]);
  50         }
  51     }
  52
  53     const std::size_t res = search_for_symbols(plugins);
  54     BOOST_ASSERT(res == 1);
  55     (void)res;
  56 }