Unique var name with C/C++ macros
Posted by: nico on 
Jun 25th, 2009 | 
Filed under: C++, Programming
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So, you’re working on some macro magic incantation and you need a unique variable name in you C program? Though it may seem simple at first, using __LINE__ for a variable name, the ## operator (concatenation in the preprocesor) won’t let you. There’s a secret spell to do it anyway: |
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// Do magic! Creates a unique name using the line number
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#define LINE_NAME( prefix ) JOIN( prefix, __LINE__ )
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#define JOIN( symbol1, symbol2 ) _DO_JOIN( symbol1, symbol2 )
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#define _DO_JOIN( symbol1, symbol2 ) symbol1##symbol2
Great, now you can keep obscuring your programs even more – have fun!
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