Maarten Kronenburg escreveu:
Thanks for your comments. The integer is not a drop-in replacement for any base type; because it accesses its data through a pointer, and has to check on certain conditions and carries etc, it is much slower than the base types.
He meant by "drop-in replacement" that an integer object should behave exactly like an int object, so that we could just replace int i; by integer i; and everything just work like magic. That would be highly desirable.
A conversion operator will generate ambiguities in expressions, even a bool conversion operator, because bool can be implicitly converted to int.
That can be avoided with the trick mentioned by the parent:
First, an operator unspecified_bool_type(), like the one found in shared_ptr.
The trick involves a pointer-to-member; those are not implicitly convertible to int, but are "testable for nullness". The unique_ptr proposal also uses this trick. -- Pedro Lamarão