Swap q(pow) -> std::pow

src/analysis/interpolation/CloughTocherInterpolator.cc

@@ -64,7 +64,7 @@ double CloughTocherInterpolator::calcBernsteinPoly( int n, int i, int j, int k,
     return 0;
   }
 
-  double result = MathUtils::faculty( n ) * qPow( u, i ) * qPow( v, j ) * qPow( w, k ) / ( MathUtils::faculty( i ) * MathUtils::faculty( j ) * MathUtils::faculty( k ) );
+  double result = MathUtils::faculty( n ) * std::pow( u, i ) * std::pow( v, j ) * std::pow( w, k ) / ( MathUtils::faculty( i ) * MathUtils::faculty( j ) * MathUtils::faculty( k ) );
   return result;
 }
 

src/analysis/interpolation/MathUtils.cc

@@ -107,7 +107,7 @@ double MathUtils::calcBernsteinPoly( int n, int i, double t )
     return 0;
   }
 
-  return lower( n, i ) * qPow( t, i ) * qPow( ( 1 - t ), ( n - i ) );
+  return lower( n, i ) * std::pow( t, i ) * std::pow( ( 1 - t ), ( n - i ) );
 }
 
 double MathUtils::cFDerBernsteinPoly( int n, int i, double t )

src/analysis/interpolation/qgsidwinterpolator.cpp

@@ -50,7 +50,7 @@ int QgsIDWInterpolator::interpolatePoint( double x, double y, double &result )
       result = vertex_it.z;
       return 0;
     }
-    currentWeight = 1 / ( pow( distance, mDistanceCoefficient ) );
+    currentWeight = 1 / ( std::pow( distance, mDistanceCoefficient ) );
     sumCounter += ( currentWeight * vertex_it.z );
     sumDenominator += currentWeight;
   }

src/analysis/raster/qgskde.cpp

@@ -181,7 +181,7 @@ QgsKernelDensityEstimation::Result QgsKernelDensityEstimation::addFeature( const
         double pixelCentroidX = ( xPosition + xp + 0.5 ) * mPixelSize + mBounds.xMinimum();
         double pixelCentroidY = ( yPosition + yp + 0.5 ) * mPixelSize + mBounds.yMinimum();
 
-        double distance = sqrt( pow( pixelCentroidX - ( *pointIt ).x(), 2.0 ) + pow( pixelCentroidY - ( *pointIt ).y(), 2.0 ) );
+        double distance = sqrt( std::pow( pixelCentroidX - ( *pointIt ).x(), 2.0 ) + std::pow( pixelCentroidY - ( *pointIt ).y(), 2.0 ) );
 
         // is pixel outside search bandwidth of feature?
         if ( distance > radius )
@@ -324,13 +324,13 @@ double QgsKernelDensityEstimation::quarticKernel( const double distance, const d
     case OutputScaled:
     {
       // Normalizing constant
-      double k = 116. / ( 5. * M_PI * pow( bandwidth, 2 ) );
+      double k = 116. / ( 5. * M_PI * std::pow( bandwidth, 2 ) );
 
       // Derived from Wand and Jones (1995), p. 175
-      return k * ( 15. / 16. ) * pow( 1. - pow( distance / bandwidth, 2 ), 2 );
+      return k * ( 15. / 16. ) * std::pow( 1. - std::pow( distance / bandwidth, 2 ), 2 );
     }
     case OutputRaw:
-      return pow( 1. - pow( distance / bandwidth, 2 ), 2 );
+      return pow( 1. - std::pow( distance / bandwidth, 2 ), 2 );
   }
   return 0.0; //no, seriously, I told you NO WARNINGS!
 }
@@ -342,13 +342,13 @@ double QgsKernelDensityEstimation::triweightKernel( const double distance, const
     case OutputScaled:
     {
       // Normalizing constant
-      double k = 128. / ( 35. * M_PI * pow( bandwidth, 2 ) );
+      double k = 128. / ( 35. * M_PI * std::pow( bandwidth, 2 ) );
 
       // Derived from Wand and Jones (1995), p. 175
-      return k * ( 35. / 32. ) * pow( 1. - pow( distance / bandwidth, 2 ), 3 );
+      return k * ( 35. / 32. ) * std::pow( 1. - std::pow( distance / bandwidth, 2 ), 3 );
     }
     case OutputRaw:
-      return pow( 1. - pow( distance / bandwidth, 2 ), 3 );
+      return pow( 1. - std::pow( distance / bandwidth, 2 ), 3 );
   }
   return 0.0; // this is getting ridiculous... don't you ever listen to a word I say?
 }
@@ -360,13 +360,13 @@ double QgsKernelDensityEstimation::epanechnikovKernel( const double distance, co
     case OutputScaled:
     {
       // Normalizing constant
-      double k = 8. / ( 3. * M_PI * pow( bandwidth, 2 ) );
+      double k = 8. / ( 3. * M_PI * std::pow( bandwidth, 2 ) );
 
       // Derived from Wand and Jones (1995), p. 175
-      return k * ( 3. / 4. ) * ( 1. - pow( distance / bandwidth, 2 ) );
+      return k * ( 3. / 4. ) * ( 1. - std::pow( distance / bandwidth, 2 ) );
     }
     case OutputRaw:
-      return ( 1. - pow( distance / bandwidth, 2 ) );
+      return ( 1. - std::pow( distance / bandwidth, 2 ) );
   }
 
   return 0.0; // la la la i'm not listening
@@ -383,7 +383,7 @@ double QgsKernelDensityEstimation::triangularKernel( const double distance, cons
 
       if ( mDecay >= 0 )
       {
-        double k = 3. / ( ( 1. + 2. * mDecay ) * M_PI * pow( bandwidth, 2 ) );
+        double k = 3. / ( ( 1. + 2. * mDecay ) * M_PI * std::pow( bandwidth, 2 ) );
 
         // Derived from Wand and Jones (1995), p. 175 (with addition of decay parameter)
         return k * ( 1. - ( 1. - mDecay ) * ( distance / bandwidth ) );

src/analysis/raster/qgsrastermatrix.cpp

@@ -292,7 +292,7 @@ double QgsRasterMatrix::calculateTwoArgumentOp( TwoArgOperator op, double arg1,
       }
       else
       {
-        return qPow( arg1, arg2 );
+        return pow( arg1, arg2 );
       }
     case opEQ:
       return ( arg1 == arg2 ? 1.0 : 0.0 );

src/analysis/vector/qgszonalstatistics.cpp

@@ -309,7 +309,7 @@ int QgsZonalStatistics::calculateStatistics( QgsFeedback *feedback )
         double variance = sumSquared / featureStats.values.count();
         if ( mStatistics & QgsZonalStatistics::StDev )
         {
-          double stdev = qPow( variance, 0.5 );
+          double stdev = std::pow( variance, 0.5 );
           changeAttributeMap.insert( stdevIndex, QVariant( stdev ) );
         }
         if ( mStatistics & QgsZonalStatistics::Variance )

src/app/qgsdecorationgrid.cpp

@@ -787,7 +787,7 @@ bool QgsDecorationGrid::getIntervalFromExtent( double *values, bool useXAxis )
   if ( !qgsDoubleNear( interval, 0.0 ) )
   {
     double interval2 = 0;
-    int factor =  pow( 10, floor( log10( interval ) ) );
+    int factor =  std::pow( 10, floor( log10( interval ) ) );
     if ( factor != 0 )
     {
       interval2 = std::round( interval / factor ) * factor;

src/app/qgsdecorationscalebar.cpp

@@ -163,7 +163,7 @@ void QgsDecorationScaleBar::render( const QgsMapSettings &mapSettings, QgsRender
     // snap to integer < 10 times power of 10
     if ( mSnapping )
     {
-      double scaler = pow( 10.0, myPowerOf10 );
+      double scaler = std::pow( 10.0, myPowerOf10 );
       myActualSize = std::round( myActualSize / scaler ) * scaler;
       myScaleBarWidth = myActualSize / myMapUnitsPerPixelDouble;
     }

src/core/composer/qgscomposermapgrid.cpp

@@ -1445,7 +1445,7 @@ QString QgsComposerMapGrid::gridAnnotationString( double value, QgsComposerMapGr
   {
     QString hemisphere;
 
-    double coordRounded = std::round( value * pow( 10.0, mGridAnnotationPrecision ) ) / pow( 10.0, mGridAnnotationPrecision );
+    double coordRounded = std::round( value * std::pow( 10.0, mGridAnnotationPrecision ) ) / std::pow( 10.0, mGridAnnotationPrecision );
     if ( coord == QgsComposerMapGrid::Longitude )
     {
       //don't use E/W suffixes if ambiguous (e.g., 180 degrees)

src/core/composer/qgscomposernodesitem.cpp

@@ -50,7 +50,7 @@ QgsComposerNodesItem::QgsComposerNodesItem( const QString &tagName,
 double QgsComposerNodesItem::computeDistance( QPointF pt1,
     QPointF pt2 ) const
 {
-  return sqrt( pow( pt1.x() - pt2.x(), 2 ) + pow( pt1.y() - pt2.y(), 2 ) );
+  return sqrt( std::pow( pt1.x() - pt2.x(), 2 ) + std::pow( pt1.y() - pt2.y(), 2 ) );
 }
 
 bool QgsComposerNodesItem::addNode( QPointF pt,

src/core/composer/qgscomposerscalebar.cpp

@@ -262,14 +262,14 @@ void QgsComposerScaleBar::refreshDataDefinedProperty( const QgsComposerObject::D
 // nextNiceNumber(4573.23, d) = 5000 (d=1) -> 4600 (d=10) -> 4580 (d=100) -> 4574 (d=1000) -> etc
 inline double nextNiceNumber( double a, double d = 1 )
 {
-  double s = qPow( 10.0, floor( log10( a ) ) ) / d;
+  double s = std::pow( 10.0, floor( log10( a ) ) ) / d;
   return ceil( a / s ) * s;
 }
 
 // prevNiceNumber(4573.23, d) = 4000 (d=1) -> 4500 (d=10) -> 4570 (d=100) -> 4573 (d=1000) -> etc
 inline double prevNiceNumber( double a, double d = 1 )
 {
-  double s = qPow( 10.0, floor( log10( a ) ) ) / d;
+  double s = std::pow( 10.0, floor( log10( a ) ) ) / d;
   return floor( a / s ) * s;
 }
 
@@ -474,7 +474,7 @@ void QgsComposerScaleBar::applyDefaultSize( QgsUnitTypes::DistanceUnit u )
 
     double segmentWidth = initialUnitsPerSegment / upperMagnitudeMultiplier;
     int segmentMagnitude = floor( log10( segmentWidth ) );
-    double unitsPerSegment = upperMagnitudeMultiplier * ( qPow( 10.0, segmentMagnitude ) );
+    double unitsPerSegment = upperMagnitudeMultiplier * ( std::pow( 10.0, segmentMagnitude ) );
     double multiplier = floor( ( widthInSelectedUnits / ( unitsPerSegment * 10.0 ) ) / 2.5 ) * 2.5;
 
     if ( multiplier > 0 )

src/core/effects/qgsimageoperation.cpp

@@ -290,7 +290,7 @@ void QgsImageOperation::HueSaturationPixelOperation::operator()( QRgb &rgb, cons
   {
     // Raising the saturation. Use a saturation curve to prevent
     // clipping at maximum saturation with ugly results.
-    s = qMin( static_cast< int >( 255. * ( 1 - qPow( 1 - ( s / 255. ), qPow( mSaturation, 2 ) ) ) ), 255 );
+    s = qMin( static_cast< int >( 255. * ( 1 - std::pow( 1 - ( s / 255. ), std::pow( mSaturation, 2 ) ) ) ), 255 );
   }
 
   if ( mColorize )

src/core/effects/qgsimageoperation.h

@@ -375,7 +375,7 @@ class CORE_EXPORT QgsImageOperation
           , mSpread( spread )
           , mProperties( properties )
         {
-          mSpreadSquared = qPow( mSpread, 2.0 );
+          mSpreadSquared = std::pow( mSpread, 2.0 );
         }
 
         void operator()( QRgb &rgb, const int x, const int y );

src/core/expression/qgsexpressionfunction.cpp

@@ -402,7 +402,7 @@ static QVariant fcnExpScale( const QVariantList &values, const QgsExpressionCont
   }
 
   // Return exponentially scaled value
-  return QVariant( ( ( rangeMax - rangeMin ) / pow( domainMax - domainMin, exponent ) ) * pow( val - domainMin, exponent ) + rangeMin );
+  return QVariant( ( ( rangeMax - rangeMin ) / std::pow( domainMax - domainMin, exponent ) ) * std::pow( val - domainMin, exponent ) + rangeMin );
 }
 
 static QVariant fcnMax( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent )
@@ -2883,7 +2883,7 @@ static QVariant fcnRound( const QVariantList &values, const QgsExpressionContext
   if ( values.length() == 2 && values.at( 1 ).toInt() != 0 )
   {
     double number = QgsExpressionUtils::getDoubleValue( values.at( 0 ), parent );
-    double scaler = pow( 10.0, QgsExpressionUtils::getIntValue( values.at( 1 ), parent ) );
+    double scaler = std::pow( 10.0, QgsExpressionUtils::getIntValue( values.at( 1 ), parent ) );
     return QVariant( std::round( number * scaler ) / scaler );
   }
 

src/core/expression/qgsexpressionnodeimpl.cpp

@@ -279,7 +279,7 @@ QVariant QgsExpressionNodeBinaryOperator::evalNode( QgsExpression *parent, const
         ENSURE_NO_EVAL_ERROR;
         double fR = QgsExpressionUtils::getDoubleValue( vR, parent );
         ENSURE_NO_EVAL_ERROR;
-        return QVariant( pow( fL, fR ) );
+        return QVariant( std::pow( fL, fR ) );
       }
 
     case boAnd:

src/core/geometry/qgsellipse.cpp

@@ -64,7 +64,7 @@ QgsEllipse QgsEllipse::fromFoci( const QgsPoint &pt1, const QgsPoint &pt2, const
   QgsPoint center = QgsGeometryUtils::midpoint( pt1, pt2 );
 
   double axis_a = dist / 2.0;
-  double axis_b = sqrt( pow( axis_a, 2.0 ) - pow( dist_p1p2 / 2.0, 2.0 ) );
+  double axis_b = sqrt( std::pow( axis_a, 2.0 ) - std::pow( dist_p1p2 / 2.0, 2.0 ) );
 
   return QgsEllipse( center, axis_a, axis_b, azimuth );
 }

src/core/geometry/qgsgeometryutils.cpp

@@ -451,7 +451,7 @@ void QgsGeometryUtils::circleCenterRadius( const QgsPoint &pt1, const QgsPoint &
   {
     centerX = ( pt1.x() + pt2.x() ) / 2.0;
     centerY = ( pt1.y() + pt2.y() ) / 2.0;
-    radius = sqrt( pow( centerX - pt1.x(), 2.0 ) + pow( centerY - pt1.y(), 2.0 ) );
+    radius = sqrt( std::pow( centerX - pt1.x(), 2.0 ) + std::pow( centerY - pt1.y(), 2.0 ) );
     return;
   }
 
@@ -461,8 +461,8 @@ void QgsGeometryUtils::circleCenterRadius( const QgsPoint &pt1, const QgsPoint &
   dx31 = pt3.x() - pt1.x();
   dy31 = pt3.y() - pt1.y();
 
-  h21 = pow( dx21, 2.0 ) + pow( dy21, 2.0 );
-  h31 = pow( dx31, 2.0 ) + pow( dy31, 2.0 );
+  h21 = std::pow( dx21, 2.0 ) + std::pow( dy21, 2.0 );
+  h31 = std::pow( dx31, 2.0 ) + std::pow( dy31, 2.0 );
 
   // 2*Cross product, d<0 means clockwise and d>0 counterclockwise sweeping angle
   d = 2 * ( dx21 * dy31 - dx31 * dy21 );
@@ -477,7 +477,7 @@ void QgsGeometryUtils::circleCenterRadius( const QgsPoint &pt1, const QgsPoint &
   // Calculate centroid coordinates and radius
   centerX = pt1.x() + ( h21 * dy31 - h31 * dy21 ) / d;
   centerY = pt1.y() - ( h21 * dx31 - h31 * dx21 ) / d;
-  radius = sqrt( pow( centerX - pt1.x(), 2.0 ) + pow( centerY - pt1.y(), 2.0 ) );
+  radius = sqrt( std::pow( centerX - pt1.x(), 2.0 ) + std::pow( centerY - pt1.y(), 2.0 ) );
 }
 
 bool QgsGeometryUtils::circleClockwise( double angle1, double angle2, double angle3 )

src/core/geometry/qgsgeos.cpp

@@ -2635,7 +2635,7 @@ int QgsGeos::lineContainedInLine( const GEOSGeometry *line1, const GEOSGeometry
     return -1;
   }
 
-  double bufferDistance = pow( 10.0L, geomDigits( line2 ) - 11 );
+  double bufferDistance = std::pow( 10.0L, geomDigits( line2 ) - 11 );
 
   GEOSGeometry *bufferGeom = GEOSBuffer_r( geosinit.ctxt, line2, bufferDistance, DEFAULT_QUADRANT_SEGMENTS );
   if ( !bufferGeom )
@@ -2665,7 +2665,7 @@ int QgsGeos::pointContainedInLine( const GEOSGeometry *point, const GEOSGeometry
   if ( !point || !line )
     return -1;
 
-  double bufferDistance = pow( 10.0L, geomDigits( line ) - 11 );
+  double bufferDistance = std::pow( 10.0L, geomDigits( line ) - 11 );
 
   GEOSGeometry *lineBuffer = GEOSBuffer_r( geosinit.ctxt, line, bufferDistance, 8 );
   if ( !lineBuffer )

src/core/geometry/qgslinestring.cpp

@@ -679,8 +679,8 @@ void QgsLineString::extend( double startDistance, double endDistance )
   // start of line
   if ( startDistance > 0 )
   {
-    double currentLen = sqrt( qPow( mX.at( 0 ) - mX.at( 1 ), 2 ) +
-                              qPow( mY.at( 0 ) - mY.at( 1 ), 2 ) );
+    double currentLen = sqrt( std::pow( mX.at( 0 ) - mX.at( 1 ), 2 ) +
+                              std::pow( mY.at( 0 ) - mY.at( 1 ), 2 ) );
     double newLen = currentLen + startDistance;
     mX[ 0 ] = mX.at( 1 ) + ( mX.at( 0 ) - mX.at( 1 ) ) / currentLen * newLen;
     mY[ 0 ] = mY.at( 1 ) + ( mY.at( 0 ) - mY.at( 1 ) ) / currentLen * newLen;
@@ -689,8 +689,8 @@ void QgsLineString::extend( double startDistance, double endDistance )
   if ( endDistance > 0 )
   {
     int last = mX.size() - 1;
-    double currentLen = sqrt( qPow( mX.at( last ) - mX.at( last - 1 ), 2 ) +
-                              qPow( mY.at( last ) - mY.at( last - 1 ), 2 ) );
+    double currentLen = sqrt( std::pow( mX.at( last ) - mX.at( last - 1 ), 2 ) +
+                              std::pow( mY.at( last ) - mY.at( last - 1 ), 2 ) );
     double newLen = currentLen + endDistance;
     mX[ last ] = mX.at( last - 1 ) + ( mX.at( last ) - mX.at( last - 1 ) ) / currentLen * newLen;
     mY[ last ] = mY.at( last - 1 ) + ( mY.at( last ) - mY.at( last - 1 ) ) / currentLen * newLen;
@@ -916,8 +916,8 @@ QgsPoint QgsLineString::centroid() const
   {
     double currentX = mX.at( i );
     double currentY = mY.at( i );
-    double segmentLength = sqrt( qPow( currentX - prevX, 2.0 ) +
-                                 qPow( currentY - prevY, 2.0 ) );
+    double segmentLength = sqrt( std::pow( currentX - prevX, 2.0 ) +
+                                 std::pow( currentY - prevY, 2.0 ) );
     if ( qgsDoubleNear( segmentLength, 0.0 ) )
       continue;
 

src/core/pal/feature.cpp

@@ -1161,7 +1161,7 @@ int FeaturePart::createCurvedCandidatesAlongLine( QList< LabelPosition * > &lPos
     if ( i == 0 )
       path_distances[i] = 0;
     else
-      path_distances[i] = sqrt( pow( old_x - mapShape->x[i], 2 ) + pow( old_y - mapShape->y[i], 2 ) );
+      path_distances[i] = sqrt( std::pow( old_x - mapShape->x[i], 2 ) + std::pow( old_y - mapShape->y[i], 2 ) );
     old_x = mapShape->x[i];
     old_y = mapShape->y[i];
 
@@ -1808,13 +1808,13 @@ bool FeaturePart::nextCharPosition( double charWidth, double segment_length, Poi
       dx = new_x - old_x;
       dy = new_y - old_y;
     }
-    while ( sqrt( pow( start_x - new_x, 2 ) + pow( start_y - new_y, 2 ) ) < charWidth ); // Distance from start_ to new_
+    while ( sqrt( std::pow( start_x - new_x, 2 ) + std::pow( start_y - new_y, 2 ) ) < charWidth ); // Distance from start_ to new_
 
     // Calculate the position to place the end of the character on
     GeomFunction::findLineCircleIntersection( start_x, start_y, charWidth, old_x, old_y, new_x, new_y, end_x, end_y );
 
     // Need to calculate distance on the new segment
-    distance = sqrt( pow( old_x - end_x, 2 ) + pow( old_y - end_y, 2 ) );
+    distance = sqrt( std::pow( old_x - end_x, 2 ) + std::pow( old_y - end_y, 2 ) );
   }
   return true;
 }

src/core/pal/pal.cpp

@@ -356,7 +356,7 @@ Problem *Pal::extract( double lambda_min, double phi_min, double lambda_max, dou
     feat = fFeats->takeFirst();
 
     prob->featStartId[i] = idlp;
-    prob->inactiveCost[i] = pow( 2, 10 - 10 * feat->priority );
+    prob->inactiveCost[i] = std::pow( 2, 10 - 10 * feat->priority );
 
     switch ( feat->feature->getGeosType() )
     {

src/core/pal/rtree.hpp

@@ -1180,7 +1180,7 @@ namespace pal
     }
     else
     {
-      return static_cast< ELEMTYPEREAL >( pow( radius, NUMDIMS ) * m_unitSphereVolume );
+      return static_cast< ELEMTYPEREAL >( std::pow( radius, NUMDIMS ) * m_unitSphereVolume );
     }
   }
 

src/core/qgis.h

@@ -236,7 +236,7 @@ inline bool qgsDoubleNearSig( double a, double b, int significantDigits = 10 )
   double br = frexp( b, &bexp );
 
   return aexp == bexp &&
-         std::round( ar * pow( 10.0, significantDigits ) ) == std::round( br * pow( 10.0, significantDigits ) );
+         std::round( ar * std::pow( 10.0, significantDigits ) ) == std::round( br * std::pow( 10.0, significantDigits ) );
 }
 
 /**
@@ -246,7 +246,7 @@ inline bool qgsDoubleNearSig( double a, double b, int significantDigits = 10 )
  */
 inline double qgsRound( double number, double places )
 {
-  int scaleFactor = pow( 10, places );
+  int scaleFactor = std::pow( 10, places );
   return static_cast<double>( static_cast<qlonglong>( number * scaleFactor + 0.5 ) ) / scaleFactor;
 }
 

src/core/qgscoordinatetransform.cpp

@@ -352,7 +352,7 @@ QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle &r
   // even with 1000 points it takes < 1ms
   // TODO: how to effectively and precisely reproject bounding box?
   const int nPoints = 1000;
-  double d = sqrt( ( rect.width() * rect.height() ) / pow( sqrt( static_cast< double >( nPoints ) ) - 1, 2.0 ) );
+  double d = sqrt( ( rect.width() * rect.height() ) / std::pow( sqrt( static_cast< double >( nPoints ) ) - 1, 2.0 ) );
   int nXPoints = static_cast< int >( ceil( rect.width() / d ) ) + 1;
   int nYPoints = static_cast< int >( ceil( rect.height() / d ) ) + 1;
 

src/core/qgsfield.cpp

@@ -268,7 +268,7 @@ bool QgsField::convertCompatible( QVariant &v ) const
 
   if ( d->type == QVariant::Double && d->precision > 0 )
   {
-    double s = qPow( 10, d->precision );
+    double s = std::pow( 10, d->precision );
     double d = v.toDouble() * s;
     v = QVariant( ( d < 0 ? ceil( d - 0.5 ) : floor( d + 0.5 ) ) / s );
     return true;

src/core/qgshistogram.cpp

@@ -65,7 +65,7 @@ bool QgsHistogram::setValues( const QgsVectorLayer *layer, const QString &fieldO
 double QgsHistogram::optimalBinWidth() const
 {
   //Freedman-Diaconis rule
-  return 2.0 * mIQR * qPow( mValues.count(), -1 / 3.0 );
+  return 2.0 * mIQR * std::pow( mValues.count(), -1 / 3.0 );
 }
 
 int QgsHistogram::optimalNumberBins() const