Initialisation of static vector
In C++03, the easiest way was to use a factory function:
std::vector<int> MakeVector()
{
std::vector v;
v.push_back(4);
v.push_back(17);
v.push_back(20);
return v;
}
std::vector Foo::MyVector = MakeVector(); // can be const if you like
"Return value optimisation" should mean that the array is filled in place, and not copied, if that is a concern. Alternatively, you could initialise from an array:
int a[] = {4,17,20};
std::vector Foo::MyVector(a, a + (sizeof a / sizeof a[0]));
If you don't mind using a non-standard library, you can use Boost.Assignment:
#include <boost/assign/list_of.hpp>
std::vector Foo::MyVector = boost::list_of(4,17,20);
In C++11 or later, you can use brace-initialisation:
std::vector Foo::MyVector = {4,17,20};
Typically, I have a class for constructing containers that I use (like this one from boost), such that you can do:
const list<int> primes = list_of(2)(3)(5)(7)(11);
That way, you can make the static const as well, to avoid accidental modifications.
For a static, you could define this in the .cc file:
// Foo.h
class Foo {
static const vector<int> something;
}
// Foo.cc
const vector<int> Foo::something = list_of(3)(5);
In C++Ox, we'll have a language mechanism to do this, using initializer lists, so you could just do:
const vector<int> primes({2, 3, 5, 7, 11});
See here.