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POType aliases in C++
 

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    <p>I have a class <code>Point</code> and a class <code>Rect</code>. I want to have two constructors for the <code>Rect</code>: One with a <code>Point</code> and a dimension (width, height) and one with two Points (top left, bottom right). Now it turns out that <code>Point</code> also can be seen as a dimension, so instead of creating a <code>Dimension</code> class I want to use my <code>Point</code>, basically like this:</p> <pre><code>class Point{...}; typedef Dimension Point; class Rect{ public: Rect(Point, Point); Rect(Point, Dimension); } </code></pre> <p>So the question is: Does the compiler make a difference between <code>Point</code> and <code>Dimension</code>? I tried it, the message ist "call of overloaded Rect(Point, Point) is ambiguous.". </p> <p>How should I do that? Preferably without inheritance :)</p> <p><strong>EDIT</strong></p> <p>I understood now that it's the same to the compiler. But there is another scenario wher I need that.</p> <p>I have a Point. The coordinates can be in a carthesian system (x, y) or GPS coordinates (lon, lat). It's perfectly ok for me to call the components <code>x0</code> and <code>x1</code> so I want to use only one class. </p> <p>Now I want to calculate the distance between the two points and my idea is as follows:</p> <pre><code>typedef PointLonLat Point; typedef PointXY Point; double distance(PointLonLat, PointLonLat); double distance(PointXY, PointXY); PointLonLat p1(10, 10); PointLonLat p2(11, 11); double dist = distance(p1, p2); // the correct implementation is used </code></pre> <p>I know it doesn't work like that. But would the answer to that also be "make two classes"?</p>
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    1. COPoint and dimension are same to the compiler.Why would you need two declarations?
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    2. CO@bashrc: Presumably because initialization differs for the two cases (you can specify a rectangle using two points, or one point and it's dimensions - the calculations are different for these two cases).
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    3. COso why typedef Point to Dimension?Another class should be added for Dimension then? From design point of view both appear to be different to me.
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