The macro BOOST_DLL_ALIAS does not appear to work for tutorial 1.

[Levi-Armstrong]

The code below suggest that you can replace it with BOOST_DLL_ALIAS(my_namespace::plugin, plugin), but if you do it will not build. Is there something missing?

// Exporting `my_namespace::plugin` variable with alias name `plugin`
// (Has the same effect as `BOOST_DLL_ALIAS(my_namespace::plugin, plugin)`)
extern "C" BOOST_SYMBOL_EXPORT my_plugin_sum plugin;
my_plugin_sum plugin;