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From: b91926@fsgm01.fnal.gov (David Sachs)
Newsgroups: comp.std.c++
Subject: Re: compile time consts
Date: 19 Sep 1994 10:14:33 -0500
Organization: FERMILAB, Batavia, IL
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dcb@lovat.fmrco.com (David Binderman) writes:

>Hello there,

>I claim the following is legal code. Three compilers disagree with me. 
>Who is correct ?

>#include <math.h>

>const int N = 1000;
>const int Q = (int) sqrt( (double) N);
>int a[ Q];

Your code is incorrect. With most compilers, Q cannot be
evaluated at compile time, because its value involves a
call to a library routine, sqrt. Therefore the compiler
cannot determine the size of array a.