What is the easiest way to initialize a std::vector with hardcoded elements?

If your compiler supports C++11, you can simply do:

std::vector<int> v = {1, 2, 3, 4};

This is available in GCC as of version 4.4. Unfortunately, VC++ 2010 seems to be lagging behind in this respect.

Alternatively, the Boost.Assign library uses non-macro magic to allow the following:

#include <boost/assign/list_of.hpp>
...
std::vector<int> v = boost::assign::list_of(1)(2)(3)(4);

Or:

#include <boost/assign/std/vector.hpp>
using namespace boost::assign;
...
std::vector<int> v;
v += 1, 2, 3, 4;

But keep in mind that this has some overhead (basically, list_of constructs a std::deque under the hood) so for performance-critical code you'd be better off doing as Yacoby says.

One method would be to use the array to initialize the vector

static const int arr[] = {16,2,77,29};
vector<int> vec (arr, arr + sizeof(arr) / sizeof(arr[0]) );

If you can, use the modern C++[11,14,17,...] way:

std::vector<int> vec = {10,20,30};

The old way of looping over a variable-length array or using sizeof() is truly terrible on the eyes and completely unnecessary in terms of mental overhead. Yuck.