Is there anything wrong with the way that this C++ header is laid out?

#pragma once
#include "LudoCore/Singleton.h"

class LudoTimer : public Singleton<LudoTimer>
{
    friend cl开发者_StackOverflowass Singleton<LudoTimer>;

public:
    void Update();
    void ShortenDay();
    void LengthenDay();
    UINT64 GetDeltaTime() const;
    float GetPercentageOfDayElapsed() const;

private:
    LudoTimer();
    ~LudoTimer();

    UINT64 GetTickCount64() const;
    UINT64 GetElapsedSeconds() const;

    UINT64 m_DeltaTime;

    // Tick Count
    UINT64 m_CurrFrameTick;
    UINT64 m_LastFrameTick;

    int m_SecondsInADay;
    static const int SHORTEST_POSSIBLE_DAY = 60;
    static const int LONGEST_POSSIBLE_DAY = 86400;
    static const int CHANGING_INTERVAL = 600;
};

To me, the above code looks normal. However, I'm new to C++ so I may be missing some nuance. I'm getting a bunch of compiler errors from it, such as:

error C2447: '{' : missing function header (old-style formal list?)

and

error C2236: unexpected 'class' 'LudoTimer'. Did you forget a ';'?

What gives!

Have a look in the other header (LudoCore/Singleton.h). The second error implies that the error is before the class LudoTimer declaration at the top.

My guess is that Singleton.h defines a class, and there's a missing ';' after that class definition.

The error is probably in LudoCore/Singleton.h or something else included earlier. Make sure your class definitions have ; semicolons after them and all that.

Quick test: comment out the #include and stick a template<class C> class Singleton; predeclaration there instead. If the compiler now complains about incomplete types, I'm right, and if not, post more details.

Well, the following compiles fine for me, so the error is very likely not in the code you showed us. I suggest you have a second look at Mike's suggestion that there is an error in Singleton.h.

//#include "LudoCore/Singleton.h"
#include <windows.h>

template< typename T >
class Singleton {};

class LudoTimer : public Singleton<LudoTimer>
{
    friend class Singleton<LudoTimer>;
public:
    void Update();
    void ShortenDay();
    void LengthenDay();
    UINT64 GetDeltaTime() const;
    float GetPercentageOfDayElapsed() const;
private:
    LudoTimer();
    ~LudoTimer();

    UINT64 GetTickCount64() const;
    UINT64 GetElapsedSeconds() const;

    UINT64 m_DeltaTime;

    // Tick Count
    UINT64 m_CurrFrameTick;
    UINT64 m_LastFrameTick;

    int m_SecondsInADay;
    static const int SHORTEST_POSSIBLE_DAY = 60;
    static const int LONGEST_POSSIBLE_DAY = 86400;
    static const int CHANGING_INTERVAL = 600;
};

I was wondering if LudoTimer is declared at the point that it is used by Singleton and if a forward declaration would help? I didn't need one in VisualStudio 2005 and like sbi I could compile the code by supplying a declaration of Singleton. If I added a simplistic implementation I could even do:

    LudoTimer* timer = Singleton<LudoTimer>::instance();

One more thing:

    error C2236: unexpected 'class' 'LudoTimer'. Did you forget a ';'?

You could try adding a semicolon on a blank line after the #include to answer this question. If it helps then you can show that there is a problem in the header file without needing to edit it.