lokinet/llarp/win32/dll.hpp

#pragma once
#include <windows.h>
#include "exception.hpp"
#include <llarp/util/str.hpp>

namespace llarp::win32
{
  namespace detail
  {
    HMODULE
    load_dll(const std::string& dll);

    template <typename Func, typename... More>
    void
    load_funcs(HMODULE handle, const std::string& name, Func*& f, More&&... more)
    {
      if (auto ptr = GetProcAddress(handle, name.c_str()))
        f = reinterpret_cast<Func*>(ptr);
      else
        throw win32::error{fmt::format("function '{}' not found", name)};
      if constexpr (sizeof...(More) > 0)
        load_funcs(handle, std::forward<More>(more)...);
    }
  }  // namespace detail

  // Loads a DLL and extracts function pointers from it.  Takes the dll name and pairs of
  // name/function pointer arguments.  Throws on failure.
  template <typename Func, typename... More>
  void
  load_dll_functions(const std::string& dll, const std::string& fname, Func*& f, More&&... funcs)
  {
    detail::load_funcs(detail::load_dll(dll), fname, f, std::forward<More>(funcs)...);
  }
}  // namespace llarp::win32