array of const pointers

Question

I guess this is a very basic question.

when I declare a vector of const pointers, like this:

vector<const SomeClass*> vec;

Is it a declaration that the pointers are const or the objects that are pointed to by the array element?

thanks

I think you might find this particular page of the C++ FAQ useful. http://www.parashift.com/c++-faq/const-correctness.html — James Matta, Dec 31 '14 at 19:49
possible duplicate of [what is the difference between const int\*, const int \* const, int const \*](http://stackoverflow.com/questions/1143262/what-is-the-difference-between-const-int-const-int-const-int-const) — OMGtechy, Dec 31 '14 at 20:45

ravi · Answer 1 · 2014-12-31T19:48:03.237

2

vector<const SomeClass*> vec;

It's declaring a vector containing pointers to const objects of type SomeClass.

edited Dec 31 '14 at 19:48

answered Dec 31 '14 at 19:41

ravi

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score 2 · Accepted Answer · answered Dec 31 '14 at 19:43

There are two places the const could go:

T* p1;                  // non-const pointer, non-const object
T const* p2;            // non-const pointer, const object
T* const p3;            // const pointer, non-const object
T const* const p4;      // const pointer, const object

Just read from right-to-left. For this reason, it becomes clearer if you write types as T const instead of const T (although in my code personally I still prefer const T).

You are specifically constructing a vector of pointers to const objects. Note that you could not create a vector of const pointers, since a vector requires its elements to be copyable (or, in C++11, at least movable) and a const pointer is neither.

array of const pointers

2 Answers2