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Section: 24.5 [unord] Status: NAD Submitter: Pete Becker Opened: 2011-02-07 Last modified: 2016-01-28
Priority: Not Prioritized
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Discussion:
Tom Plum pointed out to me that there's an apparent inconsistency in the std:: qualification of template names in the unordered containers:
template <class Key,
class T,
class Hash = hash<Key>,
class Pred = std::equal_to<Key>,
class Alloc = std::allocator<std::pair<const Key, T> > >
class unordered_map;
Is there a reason that hash is not qualified with std::? TR1 also does not use std:: here.
[ 2011-02-07 Chris Jefferson adds: ]
I assumed (I might be wrong) it is because hash is designed to be a customisation point, like swap.
[ 2011-02-07 Howard Hinnant adds: ]
I think this is incorrect. We mean std::hash, though clients are free to specialize std::hash on user-defined types. With the possible exception of begin/end (which I'm not sure if we've settled that), swap is the only intended customization point (look up a function by ADL) in the std:: lib.
[ 2011-02-24 Chris Jefferson adds: ]
I recommend NAD, due to 16.4.2.2 [contents] p3:
Whenever a name x defined in the standard library is mentioned, the name x is assumed to be fully qualified as ::std::x, unless explicitly described otherwise. For example, if the Effects section for library function F is described as calling library function G, the function ::std::G is meant.
[2011-02-25 Reflector discussion]
Moved to Tentatively NAD after 5 votes.
Proposed resolution: