c++initializationstdinitializerlist

How to initialize an intializer_list?

Some cpp class accept initializer_list as input, for example:

std::map<std::string, int> m{{"CPU", 10}, {"GPU", 15}, {"RAM", 20}};

or

std::map<std::string, int> m={{"CPU", 10}, {"GPU", 15}, {"RAM", 20}};

Is it possible, to define an initializer_list variable, then use it to call the constructor? i.e. something like:

auto il = {{"CPU", 10}, {"GPU", 15}, {"RAM", 20}};

std::map<std::string, int> m = il;
Solution

  • Yes. Example:

    #include <initializer_list>
#include <map>
#include <string>

int main() {
    std::initializer_list<std::pair<const std::string, int>> il = {
        {"CPU", 10}, {"GPU", 15}, {"RAM", 20}};

    std::map<std::string, int> m = il;
}