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### 139. Optional sequence operation table description unclear

Section: 22.2.3 [sequence.reqmts] Status: TC1 Submitter: Andrew Koenig Opened: 1999-03-30 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

The sentence introducing the Optional sequence operation table (23.1.1 paragraph 12) has two problems:

A. It says ``The operations in table 68 are provided only for the containers for which they take constant time.''
That could be interpreted in two ways, one of them being ``Even though table 68 shows particular operations as being provided, implementations are free to omit them if they cannot implement them in constant time.''
B. That paragraph says nothing about amortized constant time, and it should.

Proposed resolution:

Replace the wording in 23.1.1 paragraph 12 which begins ``The operations in table 68 are provided only..." with:

> Table 68 lists sequence operations that are provided for some types of sequential containers but not others. An implementation shall provide these operations for all container types shown in the ``container'' column, and shall implement them so as to take amortized constant time.