Any negative outcome from writing a function body on a separate line?

Question

I'm reviewing our Visual C++ code base and see lots of helper functions with really short bodies. Like for example this:

inline int max( int a, int b ) { return a > b ? a : b; }

the problem is when code is debugged in Visual Studio debugger it's impossible to immediately see what a and b are upon entering the function with F11 ("step into"). One just presses F11 and the "current line" pointer points onto the line with the opening brace, then after F10 ("step over") control goes out of the function. That's not very convenient.

The alternative would be to rewrite all those function so that the body payload occupies a separate line:

inline int max( int a, int b )
{
    return a > b ? a : b;
}

now when F11 is pressed the "current line" pointer points onto the opening brace, then after F10 control passes onto the payload and one can see what values a and b have. If one doesn't care and just entered this function while some complex expression is being evaluated he can press Shift-F11 and bail out of the function - but he could do this in the former case as well, so there're no major negative changes in debugging experience.

Are there any drawbacks in such code transformation? Any reasons to keep the function body on the same line as the function signature?

Answer 1

Do you set the breakpoint by clicking on the left side of the code window? Try positioning the cursor over the return statement and pressing the appropriate keyboard shortcut instead, e.g. F9. Only a single statement should be selected as the breakpoint, just like selecting a whole line in the second sample.

Answer 2

The only reasons i can imagine are, that this is such a simple method and that the file would be bigger if you don't write the method in one line. There is nothing negative about formatting it the second way. It's only positive :)

Answer 3

There's no difference in the compiled code between the two ways of formatting your code.

Go with what ever makes it easier to debug/maintain/understand.

In this case it's having the code on a separate line.

Answer 4

From what I know, C/C++ compilers disregard white spaces, so writing the function body on another line is only for better code readability.

Answer 5

I can't reproduce your problem. In Visual Studio 2008, if I step into this function using F11, the current line pointer points to the one-liner, and I can see the values of a and b.

Which version of Visual Studio are you using?

As to your question, this is purely subjective. Personally, I prefer one-liners to be on one line. But that's just me, I like to have as much code as possible on the screen at any time.

Answer 6

IME you will keep running into this, no matter how many functions' bodies you change (thereby confusing everybody who's trying to review their changes in SVN or whatever you use). It's just too common a coding convention to completely eliminate it from a sufficiently big codebase.
And even if you managed fix all these function definitions (which is, from my POV, an uglification of the code), you will still run into code like f(g()+h(), i()) where you want to debug into the call to f() without having to go through g(), h(), and i(). Essentially, this is the same problem: some code put into a single line and you want to debug through part of it, only. Are you proposing to change (uglify) all such code, too?
You're better off learning to deal with this.

The way I deal with this in VS is to fire up the CPU window through whatever shortcut your IDE is configured to (it's Alt+8 for me) and step through the assembly instructions displayed there far enough for the stack frame to be established. If you keep the "Locals" watch window open you will be "far enough" when the local variables pop into existence. Given some time you will learn to read the machine instructions good enough to judge this just by looking at the assembler code.