shared_object.hpp

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#pragma once

#include <SDL.h>

#include <string>

#include "exception.hpp"

namespace sdl
{
class SharedObject
{
    using SharedObjectHandle = void*;
    SharedObjectHandle handle_ = nullptr;

public:
    using FunctionAddress = void*;

    SharedObject(std::string const& objectName) : handle_{SDL_LoadObject(objectName.c_str())}
    {
        if (!handle_) throw Exception("SDL_LoadObject");
    }

    SharedObject() = default;

    ~SharedObject() { SDL_UnloadObject(handle_); }

    SharedObject(SharedObject&& other) noexcept { *this = std::move(other); }

    SharedObject& operator=(SharedObject&& other) noexcept
    {
        if (handle_ != other.handle_)
        {
            // If we currently hold an object
            if (handle_)
            {
                // Free so we do not leak
                SDL_UnloadObject(handle_);
            }

            // Assign from other handle, and set it to null
            handle_       = other.handle_;
            other.handle_ = nullptr;
        }

        return *this;
    }

    SharedObject(SharedObject const&) = delete;

    SharedObject& operator=(SharedObject const&) = delete;

    FunctionAddress function_pointer(std::string const& functionName) const
    {
        const auto address = SDL_LoadFunction(handle_, functionName.c_str());
        if (!address) throw Exception("SDL_LoadFunction");
        return address;
    }

    template<typename FunctionPointerSignature>
    FunctionPointerSignature function_pointer(std::string const& functionName) const
    {
        return reinterpret_cast<FunctionPointerSignature>(function_pointer(functionName));
    }
};

} // namespace sdl