“指向最后一个元素的指针”的漂亮语法，std :: vector？

Question

I'm wondering if there is prettier syntax for this to get a normal pointer (not an iterator) to the last element in a C++ vector

std::vector<int> vec;

int* ptrToLastOne = &(*(vec.end() - 1)) ;

// the other way I could see was
int* ptrToLastOne2 = &vec[ vec.size()-1 ] ;

But these are both not very nice looking!

Answer 1

int* ptrToLastOne = &vec.back(); // precondition: !vec.empty()

Answer 2

int* ptrToLast = &(vec.back()); // Assuming the vector is not empty.

Answer 3

Some more options:

int* ptrToLast = &*vec.rbegin();

or

int* ptrToLast = &*boost::prev(vec.end());

Answer 4

Nothing much prettier for that, but you can write a templated helper function that will do the same for you internally, and this way at least the call sites will look much cleaner and you'll get lower probability for planting errors through typos.

See the accepted answer to a very similar question and what the solution might look like.