dll.hpp

#ifndef LIBFILEZILLA_GLUE_DLL_HEADER
#define LIBFILEZILLA_GLUE_DLL_HEADER
 
#include "../libfilezilla.hpp"
 
#ifdef FZ_WINDOWS
 
#include "./windows.hpp"
 
namespace fz {

class FZ_PUBLIC_SYMBOL dll final
{
public:
    explicit dll()
        : h_{}
    {}

    explicit dll(wchar_t const* name, DWORD flags)
        : h_{LoadLibraryExW(name, nullptr, flags)}
    {}

    ~dll() {
        if (h_) {
            FreeLibrary(h_);
        }
    }
 
    template<typename T>
    static dll from_address(T const& t) {
        dll d;
        if (!GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, reinterpret_cast<char const*>(t), &d.h_)) {
            d.h_ = nullptr;
        }
        return d;
    }
 
    dll(dll const&) = delete;
    dll& operator=(dll const&) = delete;
 
    dll(dll && d);
    dll& operator=(dll && d);
 
    explicit operator bool() const {
        return h_ != nullptr;
    }

    void *operator[](char const *name) const {
        return h_ ? reinterpret_cast<void*>(::GetProcAddress(h_, name)) : nullptr;
    }
 
private:
    mutable HMODULE h_{};
};

class FZ_PUBLIC_SYMBOL shdlls final
{
protected:
    shdlls();
    ~shdlls();
 
    shdlls(shdlls const&) = delete;
    shdlls* operator=(shdlls const&) = delete;
 
public:
    static shdlls& get();
 
    dll shell32_; 
    dll ole32_;   
};
 
}

#define FZ_DLL_IMPORT(dll, symbol)                                                   \
    static const auto symbol = reinterpret_cast<decltype(&::symbol)>((dll)[#symbol]) \
/***/
 
#else
#error This file is for Windows only
#endif
 
#endif