Operators on Point and Extent

The Point and Extent classes support many mathematical operators, but the set of available operators (and their expected behavior) isn’t quite as obvious as one might think. The table below lists all supported operators, with notes below on special cases. For the rationale behind these operations, see RFC-41.

LHS RHS Operator Result Notes
PointD PointD +, += Not supported [1]
PointD PointD - ExtentD  
PointD PointD -= Not supported [2]
PointD PointI - ExtentD  
PointD PointI -= Not supported [2]
PointD ExtentD +, +=, -, -= PointD  
PointD ExtentI +, +=, -, -= PointD  
PointI PointD +, += Not supported [1]
PointI PointI +, += Not supported [1]
PointI ExtentD + PointD  
PointI ExtentD += Not supported [2]
PointI ExtentI +, += PointI  
PointI PointD - ExtentD  
PointI PointD -= Not supported [2]
PointI PointI - ExtentI  
PointI PointI -= Not supported [2]
PointI ExtentD - PointD  
PointI ExtentD -= Not supported [2]
PointI ExtentI -, -= PointI  
ExtentD PointD + PointD  
ExtentD PointD += Not supported [2]
ExtentD PointD -, -= Not supported [1]
ExtentD PointI + PointD  
ExtentD PointI += Not supported [2]
ExtentD PointI -, -= Not supported [1]
ExtentD ExtentD +, +=, -, -= ExtentD  
ExtentD ExtentI +, +=, -, -= ExtentD  
ExtentI PointD + PointD  
ExtentI PointD += Not supported [2]
ExtentI PointD -, -= Not supported [1]
ExtentI PointI + PointI  
ExtentI PointI += Not supported [2]
ExtentI PointI -, -= Not supported [1]
ExtentI ExtentD +, - ExtentD  
ExtentI ExtentD +=, -= Not supported [2]
ExtentI ExtentI +, -, +=, -= ExtentI  
ExtentD double *, *=, /, /= ExtentD  
ExtentD double //, //= Not supported [4]
ExtentD int *, *=, /, /= ExtentD [3]
ExtentD int //, //= Not supported [4]
ExtentI double * ExtentD  
ExtentI double *= Not supported [2]
ExtentI double / ExtentD  
ExtentI double /= Not supported [2]
ExtentI double //, //= Not supported [4]
ExtentI int *, *= ExtentI  
ExtentI int / ExtentD  
ExtentI int /= Not supported (Python), ExtentI (C++) [2]
ExtentI int //, //= ExtentI [5]
double ExtentD * ExtentD  
double ExtentI * ExtentD  
int ExtentD * ExtentD [3]
int ExtentI * ExtentI  
[1](1, 2, 3, 4, 5, 6, 7) Operation is not geometrically meaningful.
[2](1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14) This is an in-place operator that would require the LHS type to change. That would actually be possible to implement in Python, but its behavior would be confusing.
[3](1, 2) This operator is not implemented directly in either C++ or Python, but is largely supported by the fact that an overload that takes double will also accept int (but may yield different answers for extremely large integers that cannot be represented exactly as doubles).
[4](1, 2, 3) The // operator applies only to integer types.
[5]This Python-only operation does not always produce the same result as regular division of integers in C++, because Python specifies that a//b is equivalent to floor(a/b), while C++ specifies that it should be equivalent to int(a/b). Note that floor rounds negative numbers down and int rounds them up.