Could someone tell me why constant is preferable to #define in the following code?

• constant will work on platforms without cpp (that's the big one for me :-)
• constant is package scoped. #define is not.
• With constant you have access to perl at compile time. With #define you do not.
• Different versions of cpp on different platforms do different things.
• It's unlikely to be much faster, if at all. The constant's are expanded at compile time so there is no run-time cost using either system. Starting up a cpp process may actually slow down your compile time.
• require() will include your code only once, compile in a separate lexical file scope, and in package main by default. #include will not.
• C macros are very much not first class macros IMHO. See Macros, LFSPs and LFMs for more on this.

:-)

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In reply to Re: C pre-processor in Perl by adrianh
in thread C pre-processor in Perl by dragonchild

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