Alexander Terekhov wrote:
Peter Dimov wrote:
Alexander Terekhov wrote:
Yeah, simply put, mutations of std::string object may invalidate references and iterators (with COW inspired semantics for non- const operator[]() et al. )... threads or no threads, COW or no COW.
Umm, not exactly.
int x = s[0];
(with non-const s) does not invalidate if COW isn't used,
Uhmm, that's not what the standard says.
I know what the standard says. ;-) It's still true. An uncounted string, a vector<> and an ordinary array do not invalidate and do not "write" when the above is used. COW is visible because it changes the semantics of a "non-const read". My point was that a COW-friendly class should have had class cow_friendly_string { public: char get( int i ) const; void set( int i, char ch ); }; sidestepping the above problem.