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An alternative method uses a pointer to access the vector. w = new std::vector<int>(); The new operator creates a new, empty vector of ints and returns a pointer to that vector. We assign that pointer to the pointer variable w , and use w for the remainder of the code to access the vector we created with new .
To remove first element of a vector, you can use erase() function. Pass iterator to first element of the vector as argument to erase() function.
std::vector::front Returns a reference to the first element in the vector. Unlike member vector::begin, which returns an iterator to this same element, this function returns a direct reference.
C++11 has vec.data() which has the benefit that the call is valid even if the vector is empty.
&mv_vec[0]
or
&my_vec.front()
my_vec.empty() ? 0 : &my_vec.front()
If you would like an std::out_of_range to be thrown if vector is empty, you could use
&my_vec.at(0)
&*my_vec.begin()
or
&mv_vec[0]
By taking the address of the first element, with &vec[0], as the standard (since C++03, I think) demands continous storage of std::vector elements.
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