Trailing spaces after backslash delimiter – Programmers nightmare.

Jijo Raj — Mon, 31 Mar 2008 17:58:34 +0000

Usually we used to have spaces after semi columns. Since C++ ignore whitespace, its not a problem. But in Visual C++ 6.0 that is not the case always. If you put spaces after the backslash delimiter(\), it will become one of the worst bugs that you encounter.

Usually we use backslash delimiter to concatenate lines – mostly while writing macros. See the following macro.

#define INCREMENT_AND_DECREMENT( Value ) \
    Value = Value + 1; \ » » »
    Value = Value - 1;

In the macro, instead of » char, put some tab or space and then compile. You will get a strange error as follows.

error C2501: 'Value' : missing storage-class or type specifiers

One of the defensive mechanism is – always enable “View whitespace” by pressing Ctrl+Shift+8. So take care next time and don’t spend hrs on these silly bugs as I did years before.

Note that its just a implementation behavior in Visual C++ 6.0 and may not found in other compilers or upcoming Visual C++ versions.

Thanks to Hemant for pointing out my implicit biasing towards VisualStudio 6.0. I forgot to specify that its just a Visual studio behavior.

Targeted Audience – Intermediate.

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Trailing spaces after backslash delimiter – Programmers nightmare.