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Re: Sorting in-place

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From:
Ronald J Kimball
Date:
August 7, 2001 06:05
Subject:
Re: Sorting in-place
Message ID:
20010807090518.A601120@linguist.thayer.dartmouth.edu
On Tue, Aug 07, 2001 at 03:00:52PM +0200, Bart Lateur wrote:
> BTW can anybody explain how the "magic" works? I mean: how comes that in
> 
> 	use constant DEBUG => 0;
> 	if(DEBUG) {
> 	      .... # things to do when debugging)
> 	}
> 
> that the if-block is supposed to be stripped from the compiled program,
> as if DEBUG was replaced with a literal 0? Is the compiler so smart that
> it recognizes a sub that returns a constant? It'd almost have to be that
> way.

Yes.  A subroutine that has an empty prototype and that simply returns a
constant value is inlined by the compiler.

Ronald

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