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Why is Vector<double> vdS empty after a call? [message #10309]

Sun, 01 July 2007 20:07

$$mike{is_here} is currently offline$ $mike{is_here}
Messages: 12
Registered: July 2007

Promising Member

Hi,

Earlier this week I came accross Ultimate: it's a wonderful program in all its facets. My thanks to the developpers Smile

Unfortunately I need a little help with some of its mighty basics. I tried some code, which shall process a list of <double>s, e.g. calculate its sum (yes, I'm from Perl). What amazes me is this: it looks like Vector<double> vdS is truncated after calling sum(). It looks like a single call to vdx. inside sum() is sufficient to do so. I.e. a 2nd call of "s = sum(vdS);" will result in a runtime error.

#include <Core/Core.h>
#include <iostream>

using namespace Upp;

double sum(Vector<double> vdx)
{
	double dSum = 0.0;
	for(int i = 0; i < vdx.GetCount(); i++) {
		dSum += vdx[i];
	}
	return dSum;
}

CONSOLE_APP_MAIN
{
	double s = 0.;
	Vector<double> vdS;
	int b, a;
	
	vdS.Clear(); vdS.Add(-1); vdS.Add(2); vdS.Add(-5);	
	b = vdS.GetCount();
	s = sum(vdS);
	a = vdS.GetCount();
	
	std::cout << "before: " << b << ", after: " << a << std::endl;
	// results in "before: 3, after: -1"
}

What am I missing? Can this be a matter of settings (I run MINGW Optimal with XP)? Can it be that double isn't moveable? What is better, i.e. more appropriate to do? And is there a shorthand to initialize vdS?

Thank you all in advance.

Kind regards,
Micha

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