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### 3135. [fund.ts.v3] LFTSv3 contains two redundant alias templates

Section: 99 [fund.ts.v3::meta.type.synop], 99 [fund.ts.v3::header.memory.synop] Status: Resolved Submitter: Thomas Köppe Opened: 2018-07-02 Last modified: 2020-05-03

Priority: 3

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Discussion:

Addresses: fund.ts.v3

The LFTSv3 prospective-working-paper N4758 contains two aliases that are already in C++17:

- `void_t` in 99 [fund.ts.v3::meta.type.synop]

- `uses_allocator_v` in 99 [fund.ts.v3::header.memory.synop]

I'd like to propose deleting both, but separate discussion is warranted:

`void_t` belongs with the larger "detection idiom", which has not been merged into C++17. We may prefer to keep our own local version of the alias.

`uses_allocator_v` aliases a version of `uses_allocator` that is modified by this TS. However, as specified the alias may actually end up referring to `std::uses_allocator` (because `<memory>` is included), not to `std::experimental::uses_allocator`, as may have been intended.

[2018-07-20 Priority set to 3 after reflector discussion]

[2020-05-03 Reflector discussion]

Resolved by P1210R0 accepted during the San Diego 2018 meeting.

Rationale:

Resolved by P1210R0

Proposed resolution: