How do I populate a static std::map using a static function?

Question

Basically, I want to call a static function in my class which adds an entry to a static member of type std::map.

class Foo
{
    private:
        static std::map<std::string, int, StringCompare> mymap;
    public:
        static bool addEntry(std::string id);
};

std::map<std::string, int, StringCompare> Foo::mymap;

static bool Foo::addEntry(std::string id)
{
    int a = 0;
    return (mymap.insert ( std::pair<std::string, int> (id, a))).second;
}

EDIT: Forgot to ask the question D:

When I compile this code, it gives me the error:

derp.hpp:24:41: error: cannot declare member function ‘static bool Foo::addEntry(std::string)’ to have static linkage [-fpermissive]

What do I do?

If all of the class members are going to be static, why not get rid of the class and use a namespace?, if you want to keep some functions private, just doesn't publish it on the header file. — PaperBirdMaster, Oct 04 '12 at 08:22
How do you mean "just doesn't publish it on the header file"? — StAlRuth, Oct 04 '12 at 08:26
IMHO create a class with all members static is pointless and isn't a class at all because none of the members belongs to any instance of the class. So, i think that is better to change the class with a namespace, creating both `cpp` and `h` files and publish the methods you want to be public on the header file, keeping the methods that you want to be private on the `cpp` file. — PaperBirdMaster, Oct 04 '12 at 08:30

Mark Garcia · Accepted Answer · 2012-10-04T08:22:16.130

2

For your original "question", use this:

Foo::addEntry("myId");

For your forgotten question, simply remove the static keyword.

edited Oct 04 '12 at 08:22

answered Oct 04 '12 at 08:14

Mark Garcia

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How do I populate a static std::map using a static function?

1 Answers1