Question

The following errors are always been pointing to my List.

我的班子档案

Point3D operator==(const Point3D &p1) const;

在我的档案中

bool operator==(Point3D &p1, Point3D &p2)
{
    if ( p1.getX() == p2.getX() && p1.getY() == p2.getY() && p1.getZ() == p2.getZ() )
        return true;
    else
        return false;
}

In my main file

//declaration
list<Point3D> l_3D;

l_3D.unique(); <-- the error point to this

错误信息

..... In member function  void std::list<_Tp,_Alloc>::unique() [with_Tp = Point3D,_Alloc = std:: allocator<Point3D>]:

Instantiated from here

error: could not convert  Point3D::operator==(const Point3D&) const (((const Point3D&)((const Point3D*)__next. std::_List_iterator<_Tp>::operator*[with_Tp = Point3D]())))  to  bool

To the kind souls out there, I thank you in advance.

Answer 1

在您的声明中,请将<条码>第3D改为<条码>。

Point3D operator==(const Point3D &p1) const;
^^^^^^^
should be bool

以上是你宣布运营商为成员,然后作为自由职能执行。你们必须决定什么。如果你使用成员职能,将执行改为:

bool Point3D::operator==(const Point3D &p2) const
{
    if ( getX() == p2.getX() && getY() == p2.getY() && getZ() == p2.getZ() )
        return true;
    else
        return false;
}

甚至更好(根据@同上的评论):

bool Point3D::operator==(const Point3D &p2) const
{
    return (getX() == p2.getX() && getY() == p2.getY() && getZ() == p2.getZ());
}

Generally the signature of your definition should match the signature of your declaration.

Answer 2

变化:

bool operator==(Point3D &p1, Point3D &p2)
{
    if ( p1.getX() == p2.getX() && p1.getY() == p2.getY() && p1.getZ() == p2.getZ() )
        return true;
    else
        return false;
}

To this:

bool operator==(const Point3D &p1, const Point3D &p2)
{
    if ( p1.getX() == p2.getX() && p1.getY() == p2.getY() && p1.getZ() == p2.getZ() )
        return true;
    else
        return false;
}

Answer 3

In your class file (I assume you mean a header file), you declare operator== as returning Point3D when it should be returning bool. Also, your operator== has a different number of arguments in your class (header?) file and your cpp file.

友情链接