C++ Coding Standards: 101 Rules, Guidelines, and Best Practices

78. Use vector (and string::c_str) to exchange data with non-C++ APIs

Summary

vector isn’t lost in translation: vector and string::c_str are your gateway to communicate with non-C++ APIs. But don’t assume iterators are pointers; to get the address of the element referred to by a vector<T>::iterator iter, use &*iter.

Discussion

vector (primarily) and string::c_str and string::data (secondarily) are the best way to communicate data with non-C++ APIs in general, and C libraries in particular.

vector’s storage is always contiguous, so accessing the address of its first element returns a pointer to its contents. Use &*v.begin(), &v[0], or &v.front() to get a pointer to v’s first element. To get a pointer to a vector’s n-th element, prefer to do ...