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### 3439. "`Distance`" template parameter is underspecified

Section: 23.4.3 [iterator.operations], 25.7.12 [alg.random.sample] Status: New Submitter: Jens Maurer Opened: 2020-05-01 Last modified: 2020-05-09

Priority: 3

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Discussion:

The library specification conveys pre-concept requirements on template parameters by naming, e.g. "`InputIterator`".

There is no general specification for template parameters named "`Distance`", as used by `std::advance` (see 23.4.3 [iterator.operations]). When addressing this omission, the local restriction in 25.7.12 [alg.random.sample] could possibly be removed.

See the related issue 3213 for the `Size` template parameter.

[2020-05-09; Reflector prioritization]

Set priority to 3 after reflector discussions.

Proposed resolution: