std::thread question

[angus725]

So, with about a semesters worth of C knowledge, I decided to get into C++ in the past few weeks. After a much smaller program that prints a few numbers (without the use of classes), I decided to figure out just how far I can get before I get stuck somewhere with my next program.

Ended up hitting a problem at std::thread, and could not figure out how to fix the compile time error.

A few reference pieces of code (no errors here):

enum buildingstatus
{
	NONE,
	BUILDING,
	BUILT,
};

class BuildTimerStruct
{
public:
	int TotalTime;
	int* timelefttimer;
	int buildingid;
	BuildTimerStruct();
	~BuildTimerStruct();
};

BuildTimerStruct::~BuildTimerStruct()
{
	delete this;
}

 class Planet
	{
	public:
		Planet();
		~Planet();
		void build();
		void DisplayStats();
		int PlanetID;
		static int globalplanets;
		void BuildingBuilt(int buildingtype);
		void DisplayBuildings();
		void Planet::BuildingTimer (BuildTimerStruct);
		void Planet::TimeUntilCompleteion(const int , const std::string );


	private:
		std::string name;
		buildingstatus *building;
		int timeleft;
		friend class GameSystem;
	}; 

Compile time error occurs at the std::thread declaration.

void Planet::build()
{
	int buildinginput=-1;
	std::cout << "Building menu initiated on planet " << name << "." << std::endl;
	DisplayBuildings();
	for(int ii=0; ii < MaxBuildingSelection; ii++)
		std::cout << "To build " << BLDGID(ii) << ", " << "please type in \"" << ii << "\"." << std::endl;
	std::cout << "To exit the building menu, please type in 0." << std::endl;

	while(buildinginput!=0)
	{
		std::cin >> buildinginput;

		if (buildinginput>9000)
		{
				DisplayBuildings();
				for(int iii=0; iii < MaxBuildingSelection; iii++)
					std::cout << "To build " << BLDGID(iii) << ", " << "please type in \"" << iii << "\"." << std::endl;
		}

		else if (buildinginput>0&&buildinginput<MaxBuildingSelection) 
		{
			if (building[buildinginput]!=NONE)
			{
				BuildingBuilt(buildinginput);
			}
			else
			{
				BuildTimerStruct* tempBLDGTIMER = new BuildTimerStruct;
				tempBLDGTIMER->TotalTime=(BLDGTIME(buildinginput));
				tempBLDGTIMER->timelefttimer=&timeleft;
				tempBLDGTIMER->buildingid=buildinginput;
				std::thread foo(&Planet::BuildingTimer, *tempBLDGTIMER); //Compile time error
				foo.detach();
				buildinginput=0;
				break; //to skip the rest of the junk 
			}
		}
		else
			std::cout <<"No building or invalid number selected, ";

		std::cout << "please enter a meaningful number to build or 0 to exit building menu." << std::endl;
		std::cout << "To display building menu, type a number over 9000." << std::endl;
		buildinginput=-1;
	} 
}

The timer std::thread is trying to get working:

void Planet::BuildingTimer (BuildTimerStruct Starter)
{
	this->building[Starter.buildingid]=BUILDING;

	this->timeleft=Starter.TotalTime;
	int InitialTime=clock();
	while(Starter.timelefttimer>0)
	{
		this->timeleft=this->timeleft-(clock()-InitialTime)/CLOCKS_PER_SEC;
	}
	this->building[Starter.buildingid]=BUILT;

	if (DebugMode==true)
		std::cout << BLDGID(Starter.buildingid) <<" has been built on " << name << "." <<std::endl;
}

std::thread did not like functions taking in more than 1 argument, so I made a class (instead of a struct so I can use "delete this;") to pass on arguments. A few things need to be pointers to allow the separate thread/function to change variables as it works.

When I try to compile this program, it gives me this error:

Error 1 error C2064: term does not evaluate to a function taking 1 arguments c:\program files (x86)\microsoft visual studio 11.0\vc\include\functional 1152 1

which leads me to this:

_VARIADIC_EXPAND_0X(_CLASS_BIND, , , , )

I'm clueless on what's causing std::thread to fail.

[cire]

I'm clueless on what's causing std::thread to fail.

The member function Planet::BuildingTimer is not a function that takes 1 argument. All member functions that are not static take a hidden parameter (the this pointer,) so Planet::BuildingTimer actually takes two arguments.

With a little C experience and no C++ experience you have no chance of getting threading correct. Maybe you should begin with something a little easier to get your head around. Like, the basics of classes. There are quite a few flaws in your code that suggest that might be the way to go.

[angus725]

Inclusion of the "this" pointer fixed the problem. Thanks!

Could you highlight some of the other flaws in the code so I know what are potential problems?