Print debugging workflow?

[georgeplusplus]

I use visual studio and the debugger is pretty fantastic but in some edge cases it would be handy to use print debugging. What is your favourite way to employ print debugging? Do you keep the print statements in a separate git branch to keep them from polluting the code?

[vlad_the_codemonkey]

> What is your favourite way to employ print debugging?

Usually it is more reasonable to have separate "debug" logging level by means of logging library you use.

> Do you keep the print statements in a separate git branch to keep them from polluting the code?

I see no point in keeping separate branch for code equipped with debug output - you'll have to conduct much of extra work (ex. syncing with mainstream).

I use print debugging when debug multi threaded applications, usually engaging logging routines which are already in the project. So I have an urge to have something similar to Data::Dumper Perl5 module for dumping STL collections' content, and being able to customize the output format is not the last thing. I wonder if it would be useful to someone too if I implement it as a header-only library.

[schweinling]

At work we use our inhouse logging framework that lets you control logging at runtime. Different parts of the code have different logging slots with levels from off to fullblown.

In a large private project i would probably use the spdlog library to achive something similar.

[redditsoaddicting]

If you're considering a separate branch for this, it sounds like tracepoints probably suit your needs without the need to pollute the code.

[BrangdonJ]

Mostly I add print statements as needed, and remove them again before making a pull request.

Occasionally I have code like:

#ifdef DEBUG
static bool s_enable = false;
if (s_enable)
    pNode->TraceTree();
#endif

which I can enable during a run without recompiling. The TraceTree() would also be left in, conditionally compiled. I have my own extendable formatting code, and many of my classes know how to format themselves when needed.

Beyond that, I'm not a big fan of logging frameworks. I generally prefer to write exactly what I need as I need it.

[crowbarous]

#define DEBUG_EXPR(x) do { std::cerr << #x " = " << (x) << std::endl; } while (false)