The C++ constructor std::set::set() (Initializer-List Constructor) constructs a set container with the contents of the initializer list init
Following is the declaration for std::set::set() Initializer-list constructor from std::set header.
set (initializer_list<value_type> init, const key_compare& comp = key_compare(), const allocator_type& alloc = allocator_type());
set (initializer_list<value_type> init, const key_compare& comp = key_compare(), const allocator_type& alloc = allocator_type()); set (initializer_list<value_type> init, const allocator_type& alloc = allocator_type());
alloc − Input iterator to initial position.
comp − comparison function object to use for all comparisons of keys
init − init is a initializer_list object which initializes the set container elements. Elements present in the set container are of value_type (Member Type)
Constructor never returns any value.
This member function has no effect in case any exception is thrown.
N log(N) in general, where N = init.size();
else, linear in N, i.e., O(N) if init is already sorted.
The following example shows the usage of std::set::set() (initializer_list) constructor.
#include <iostream> #include <set> #include <string> using namespace std; int main() { // Initializer list constructor std::set<std::string> fruit { "orange", "apple", "mango", "peach", "grape" }; std::cout << "Size of set container fruit is : " << fruit.size(); return 0; }
Let us compile and run the above program, this will produce the following result −
Size of set container fruit is : 5