Russian Qt Forum

C++ (Qt)
template < typename _Type, int _D >
class Point
{
    _Type m_values[_D];
}
template < typename _Type, int _D >
class Vector
{
    _Type m_values[_D];
}
 

C++ (Qt)
template < typename _Type, int _D >
class Base
{
    _Type m_values[_D+1];
}
template < typename _Type, int _D >
class Vector : public Base< _Type, _D >
{
public:
    Vector() {m_values[_D] = Type(); }
};
 
template < typename _Type, int _D >
class Point : public Base< _Type, _D >
{
public:
    Point() {m_values[_D] = Type(1); }
};
 

C++ (Qt)
vec.x = vec.x * some_constant / vec.z;
vec.y = vec.y * some_constant / vec.z;

void QPainter::drawLine(const QPoint & p1, const QPoint & p2);
void QPainter::drawLine(const QPointF & p1, const QPointF & p2);[/quote]

template <class Point>
void QPainter::drawLine(const Point & p1, const Point & p2);

C++ (Qt)
if (std::is_floating_point<pt.x()>::value) ...
или аккуратнее
if (std::is_floating_point<Point::value_type>::value) ...
или даже без С++ 11
if (typeid(Point::value_type) == typeid(float)..
 

C++ (Qt)
typedef Point<int, 2> QPoint; 
typedef Point<qreal, 2> QPointF; 
 
void QPainter::drawLine(const QPoint & p1, const QPoint & p2);
void QPainter::drawLine(const QPointF & p1, const QPointF & p2);
 

C++ (Qt)
inline void QPainter::drawLine(const QPoint &p1, const QPoint &p2)
{
    QLine l(p1, p2);
    drawLines(&l, 1);
}
 
void QPainter::drawLines(const QLine *lines, int lineCount)
{
    Q_D(QPainter);
 
    if (!d->engine || lineCount < 1)
        return;
 
    if (d->extended) {
        d->extended->drawLines(lines, lineCount);
..
 
void QRasterPaintEngine::drawLines(const QLine *lines, int lineCount)
{
    Q_D(QRasterPaintEngine);
    QRasterPaintEngineState *s = state();
 
    ensurePen();
    if (!s->penData.blend)
        return;
 
    if (s->flags.fast_pen) {
        QCosmeticStroker stroker(s, d->deviceRect, d->deviceRectUnclipped);
        stroker.setLegacyRoundingEnabled(s->flags.legacy_rounding);
        for (int i=0; i<lineCount; ++i) {
            const QLine &l = lines[i];
            stroker.drawLine(l.p1(), l.p2());
..
 
void QCosmeticStroker::drawLine(const QPointF &p1, const QPointF &p2)
{
..
 

C++ (Qt)
typedef Point<int, 2> QPoint; 
typedef Point<qreal, 2> QPointF; 
 
void QPainter::drawLine(const QPoint & p1, const QPoint & p2);
void QPainter::drawLine(const QPointF & p1, const QPointF & p2);

C++ (Qt)
void QPainter::drawLine(const QPoint & p1, const QPoint & p2)
{
 return QPainter::drawLine_template_helper(p1, p2);
}
 

C++ (Qt)
template <class T>
void SomeClass::SomeMethod( T & );