C++: can't static_cast from double* to int*

Question

When I try to use a static_cast to cast a double* to an int*, I get the following error:

invalid static_cast from type ‘double*’ to type ‘int*’

Answer 1

Aside from being pointers, double* and int* have nothing in common. You could say the same thing for Foo* and Bar* pointer types to any dissimilar structures.

static_cast means that a pointer of the source type can be used as a pointer of the destination type, which requires a subtype relationship.