std::vector as a static member

[ejohns85]

Hello,

I have a class with a vector as a static member:

class MyClass
{
     static std::vector<int> my_vector;
}

I then wish to initialize the vector in the .cpp file in global scope:

std::vector<int> my_vector = std::vector<int>(10);
my_vector[0] = 5;

But this gives me some errors. How can I initialize the values of my_vector? Thanks.

[Paul McKenzie]

Hello,

I have a class with a vector as a static member:

class MyClass
{
     static std::vector<int> my_vector;
}

I then wish to initialize the vector in the .cpp file in global scope:

std::vector<int> my_vector = std::vector<int>(10);
my_vector[0] = 5;

But this gives me some errors. How can I initialize the values of my_vector? Thanks.

What are the errors? Also, please post compilable code so we can see what you're doing.

#include <vector>
class MyClass
{
     static std::vector<int> my_vector;
};
//....
// In one CPP file outside of any function:
std::vector<int> MyClass::my_vector(10);

The code below is not initialization -- it is assignment

my_vector[0] = 5;

Therefore it must be done within a function.

Regards,

Paul McKenzie

[borko1980]

class Foo
{
public:
   static std::vector<int> v;
};
// Foo.cpp
std::vector<int> Foo::v = std::vector<int>(5);
...
int main()
{
...
   Foo::v.push_back(3);
   Foo::v.push_back(1);
   Foo::v.push_back(8);
   Foo::v.push_back(6);
   Foo::v.push_back(2);
...
   std::cout << "v[0] = " << v[0] << std::endl;
}

[Lindley]

You can use Boost.Assign:

std::vector<int> Foo::v = boost::assign::list_of(5)(10)(15)(20); // as long as you like

If you don't want that dependency, this will produce the same result:

vector<int> initializeVector()
{
    vector<int> v;
    v.push_back(5);
    v.push_back(10);
    v.push_back(15);
    v.push_back(20);
    return v;
}

std::vector<int> Foo::v = initializeVector();