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1209. match_results should be moveable

Section: 32.9.2 [re.results.const] Status: C++11 Submitter: Stephan T. Lavavej Opened: 2009-09-15 Last modified: 2016-01-28

Priority: Not Prioritized

View all other issues in [re.results.const].

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Discussion:

In Working Draft N2914, match_results lacks a move constructor and move assignment operator. Because it owns dynamically allocated memory, it should be moveable.

As far as I can tell, this isn't tracked by an active issue yet; Library Issue 723 doesn't talk about match_results.

[ 2009-09-21 Daniel provided wording. ]

[ 2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib. ]

Proposed resolution:

1. Add the following member declarations to 32.9 [re.results]/3:

   // 28.10.1, construct/copy/destroy:
   explicit match_results(const Allocator& a = Allocator());
   match_results(const match_results& m);
   match_results(match_results&& m);
   match_results& operator=(const match_results& m);
   match_results& operator=(match_results&& m);
   ~match_results();
   

2. Add the following new prototype descriptions to 32.9.2 [re.results.const] using the table numbering of N3000 (referring to the table titled "match_results assignment operator effects"):

   match_results(const match_results& m);
   

   4 Effects: Constructs an object of class match_results, as a copy of m.

   match_results(match_results&& m);
   

   5 Effects: Move-constructs an object of class match_results from m satisfying the same postconditions as Table 131. Additionally the stored Allocator value is move constructed from m.get_allocator(). After the initialization of *this sets m to an unspecified but valid state.

   6 Throws: Nothing if the allocator's move constructor throws nothing.

   match_results& operator=(const match_results& m);
   

   7 Effects: Assigns m to *this. The postconditions of this function are indicated in Table 131.

   match_results& operator=(match_results&& m);
   

   8 Effects: Move-assigns m to *this. The postconditions of this function are indicated in Table 131. After the assignment, m is in a valid but unspecified state.

   9 Throws: Nothing.