Thought Clutter

Although I currently don't use it much, I fancy myself a bit of a C++ programmer. Over the years, I've accumulated a number of neat C++ coding tricks. For example, while in graduate school, I met Jeff Squyres who taught me a neat little C++ technique that I have used often since then. Jeff's trick is a low overhead C++ debugging stream. The real beauty is that all the debug statements can be compiled out without changing the source code:

 
// Author: Jeremy Faller
// Copyright (c) 2007 Digital Sweetener, Inc.
//
// This software is distributed under the MIT license.
//   http://www.opensource.org/licenses/mit-license.php
#if !defined(DEBUGSTREAM_H_)
#define DEBUGSTREAM_H_
 
#include <iostream>
 
class DebugStream
{
    std::ostream    &mStream;
    bool            mOn;
 
public:
    DebugStream(std::ostream &str, bool isOn = true)
        : mStream(str)
        , mOn(isOn)
    { }
 
    template <class T>
    inline
    DebugStream& operator<<(const T &inVal)
    {
#if defined(DEBUG_ON_)
        if (mOn)
            mStream << inVal;
#endif
        return *this;
    }
 
    inline
    DebugStream& operator<<(std::ostream& (*inVal)(std::ostream&))
    {
#if defined(DEBUG_ON_)
        if (mOn)
            mStream << inVal;
#endif
        return *this;
    }
 
    void Reset() { mOn = true; }
    bool On() const { return mOn; }
    bool& On() { return mOn; }
};
 
extern DebugStream debug;
 
#endif // DEBUGSTREAM_H_
 

And using it is simple enough:

 
#include "debugstream.h"
 
DebugStream debug(std::cout);
 
int main()
{
    debug << "Debug" << std::endl;
    debug.On() = false;
    debug << "This line will not print" << std::endl;
    return 0;
}
 

While using DebugStream, please keep in mind that although it is threadsafe, unexpected results can occur when twiddling the On() variable.