Use std::function for callback

[ccvca]

As this library already requires C++ 14 , using std::function (https://en.cppreference.com/w/cpp/utility/functional/function) for the notifications should improve the usability a lot (e.g. bind to class members, use custom handler types, ...). As a function pointer can be bound to an std::function, too, this would not break existing code.

This would require changes in these places:

ADS/AdsLib/AdsNotificationOOI.h

Line 14 in 3824918

struct AdsNotification {

ADS/AdsLib/AdsDevice.cpp

Lines 83 to 87 in 3824918

	AdsHandle AdsDevice::GetHandle(const uint32_t indexGroup,
	const uint32_t indexOffset,
	const AdsNotificationAttrib& notificationAttributes,
	PAdsNotificationFuncEx callback,
	const uint32_t hUser) const

ADS/AdsLib/standalone/AdsLib.cpp

Lines 261 to 268 in 3824918

	long AdsSyncAddDeviceNotificationReqEx(long port,
	const AmsAddr* pAddr,
	uint32_t indexGroup,
	uint32_t indexOffset,
	const AdsNotificationAttrib* pAttrib,
	PAdsNotificationFuncEx pFunc,
	uint32_t hUser,
	uint32_t* pNotification)

ADS/AdsLib/AdsNotification.h

Line 15 in 3824918

struct Notification {

PS: I'm aware that this is a feature request, but I just want to get a general opinion about this, before I potentially work on this.

[pbruenn]

Yes, you are not the first (#142) and I agree a std::function<> interface would be much nicer. Actually this is on my todo list for quite some time, but I had no time to look into this. Important is, that we don't break existing users. So it might be easier to add a new wrapper for this. If you have a good idea, go for it. But be warned I will only merge a clean solution.

EDIT: Beware you can not change AdsSyncAddDeviceNotificationReqEx as that is part of the legacy "TcAdsLib" interface [1]. We have to keep it in sync to keep the possibility to link against upstream TwinCAT TcAdsDll.dll.

[1] https://infosys.beckhoff.com/content/1033/tcadsdll2/12444732299.html