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Boost Core Utilities
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Add pointer_traits with to_address #33

Closed glenfe closed 7 years ago

glenfe commented 7 years ago

Still working on documentation.

pdimov commented 7 years ago

So you decided to call it to_raw_pointer after all. Do we need it now that the implementation of pointer_traits doesn't use it?

boost::pointer_traits should be present even if std::pointer_traits isn't, and should work the same way, except of course rebind if aliases are unavailable. We should have a convention for that... rebind_trait? rebind_type?

glenfe commented 7 years ago

I'm on the fence between: Keeping it at all (with any name, to_raw_pointer, to_address, get_address) or dropping it. (pointer_to_address isn't too long, but the convention of to_string is nice, one less type mentioned in identifier).

I wish rebind were specified as types containing a type or other member instead of aliases, just for compatibility sake. If std::pointer_traits isn't available, should we just provide the T* specialization of pointer_traits, along with a rebind containing other?

glenfe commented 7 years ago

I've found myself writing something like the following more than once: https://github.com/boostorg/smart_ptr/blob/develop/include/boost/smart_ptr/allocate_shared_array.hpp#L134-L144

Were you thinking of something like that, but where the traits template is also specified (i.e. pointer_traits, allocator_traits)?

pdimov commented 7 years ago

If std::pointer_traits isn't available, should we just provide the T* specialization of pointer_traits, along with a rebind containing other?

I was thinking that we should provide a fully functional pointer_traits if the standard one isn't available, but with rebind replaced with a struct with some other name (rebind_type?), to not conflict with the standard one. We can supply that other name in boost::pointer_traits in the other path as well, so that code can use it without ifdefs.

Incidentally, as written boost::pointer_traits<>::rebind returns std::pointer_traits<>, so we'll have to massage that in either case.

pdimov commented 7 years ago

template<class U> using rebind = mp_rename<std::pointer_traits<T>::rebind<U>, boost::pointer_traits>; :-)

pdimov commented 7 years ago

Ah wait, this rebind returns the pointer type. Never mind.

glenfe commented 7 years ago

Merged after Peter's review and approval on Slack.