1. Revision History
1.1. Revision 0
Initial Release 🎉
To date, there have only ever been two widely used libraries that utilize
overloading the addressof operator (
). These are the
Microsoft and Boost.Spirit. Because of these two libraries (and anyone else who
might get the bright idea to "just overload the addressof operator") standard
library vendors are required to use
. This is, to be quite
frank, ridiculous. In the same way that we have to protect our code from comma
operator overloads (something that should also be deprecated and removed), we
now have to protect ourselves from one of the most common operations when
working with a systems programming language: Getting an object’s address. While
it might have made sense at one time to permit users to define their own memory
model, this approach is no longer viable. Indeed, while
the addressof operator, it also provides a function that does the same
operation. Additionally, Boost.Spirit uses it to represent a DSL from a
different syntax altogether. While they might be hard pressed to replace these,
they most likely don’t need to get the address of the types they overload with.
Eventually removing the ability to overload the addressof operator will let us
at some future date and compilers won’t have to
builtin to do what is already built into the language.
3.1. Will this break code?
No. We’re only deprecating the addressof operator. At some point in the future, it is assumed users will have migrated off of overloading the operator in favor of some function interface. At that point then we’ll remove overloading the addressof operator altogether.
3.2. What’s so bad about overloading the addressof operator?
Although it is possible to do so in the language, one will note that the
standard library at no point provides this overload itself (nor does it for
, and others). This is by design and intent. These
seemed like good ideas at the time, but it’s 2018 now (as of this writing).
Perhaps it’s time for a little pragmatism.
Wording is relative to [N4762]
In 184.108.40.206 Operators in expressions [over.match.oper], paragraph 3, add a new bullet point:
In 11.5.1 Unary Operators [over.unary] add a new paragraph
In annex D, add a new paragraph