我应该使用 boost::ptr_vector<T>或向量<boost::shared_ptr<T>>?
I need a container of pointers. Would you recommend boost::ptr_vector<T>
or std::vector<boost::shared_ptr<T> >
? (Or something else?)
If that's of interest, my actual data structure is relatively complicated (see here) and currently stores objects, not pointers, but i'd like to change that (using pointer containers), in order to get rid of unnecessary copying:
typedef std::multimap<Foo0, std::map<int, double> > VecElem;
std::vector<VecElem> vec;
解决方案
Who owns the object? If the container owns the objects (meaning the objects should not live longer than the container), use a ptr_vector
. Otherwise, use a vector of shared_ptr
s. Standard library containers (such as std::vector
or std::list
) own the objects they contain, so the semantics of a ptr_vector
is closer to that.
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