Qt Creator - error: call of overloaded 'QMatrix4x4(const qreal*&)' is ambiguous

[hasanbaghal]

I have a project in Qt Creator in Windows,When compiled I got this Error, I Googled a few, But I couldn't find the solution :

\application\src\helpers.cpp:99: error: call of overloaded 'QMatrix4x4(const qreal*&)' is ambiguous
QMatrix4x4 matrix(a);
^
the line that has error:

QMatrix4x4 matrix(a);so what should I do?

helpers.cpp corresponded to the error:

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "helpers.h"
#include <QMatrix4x4>
#include <QtGui>

Helpers :: Helpers()
{
}

Helpers :: ~Helpers()
{
}

//====================================================================
// Normalize
//====================================================================

void Helpers::normalize(qreal *a)
{
double b;

b = vlen(a);
a[0] /= b;
a[1] /= b;
a[2] /= b;
}

//====================================================================
// Length
//====================================================================

qreal Helpers::vlen(qreal *a)
{
return sqrt(a[0]*a[0] + a[1]*a[1] + a[2]*a[2]);
}

//====================================================================
// Cross product
//====================================================================

void Helpers::crossProduct(qreal *a, qreal *b, qreal *c)
{
c[0] = a[1]*b[2] - a[2]*b[1];
c[1] = a[2]*b[0] - a[0]*b[2];
c[2] = a[0]*b[1] - a[1]*b[0];
}

//====================================================================
// Invert 4x4 matrix (for visualiztion only)
//====================================================================
//commented by John
// pre start cooment
void Helpers::invertMatrix(const qreal *a, qreal *inva)
{

QMatrix4x4 matrix(a);

bool ok(true);

QMatrix4x4 inverse(matrix.transposed().inverted(&ok));

if(!ok) fprintf(stderr, "Error: Singular 4x4 matrix\n");

for(int i = 0; i < 16; ++i)
inva[i] = double(inverse.data()[i]);
}
//*/ pre end comment
This is all errors that I see,after lots of debugging... I think the problem maybe about command syntax format or libraries definition and usage or something else...