question...

[James Crotinger]

Is it safe to convert a vector<int>::const_iterator to a const int *

via something like

 

   void foo(const vector<int> &a)

   {

     const int *pBegin = &(a.begin()[0]);

   }

 

In particular, is it allowable for operator[] for a const_iterator to return by value instead of reference, in which case this would be taking the address of a temporary.

 

I’m trying to figure out a way to get the DynamicArray::destroy(begin, end, …) stuff to work reliably for both vector<int> iterators and for int pointers. Currently it is explicitly written for int pointers (there is a virtual function call in the execution path, so I can’t rely on templates here). Since vector iterators are usually typedefs to pointers, the current code will usually work for vector iterators. But on some systems, or with some compile options, it might not compile (if the iterators are implemented as classes). However, I do know that vector guarantees contiguous storage, so if there is a way to convert the iterator to an address of the corresponding element in the container, this will work regardless of the way iterators are implemented.

 

   Jim

 

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James A. Crotinger

Software Research Scientist

Proximation, LLC