Why does this code call the initializer_list constructor to initialize a string for a single character?

Question

I recently worked on a C ++ project and stumbled upon an edge case with string constructors that I cannot fully understand. The corresponding code (which you can run here ) is as follows:

#include <iostream>
#include <string>
using namespace std;

int main() {
    string directParens(1, '*');
    string directBraces{1, '*'};
    string indirectBraces = {1, '*'};

    cout << directParens.size() << endl;   // 1
    cout << directBraces.size() << endl;   // 2
    cout << indirectBraces.size() << endl; // 2
    return 0;
}

The string versions initialized in parentheses end with two characters in them: a charwith a numeric value of 1 followed by a star.

I don’t understand why strings initialized in parentheses refer to a constructor initializer_list, and not to a constructor that takes a size and a character. The constructor initializer_listhas the following signature:

basic_string(std::initializer_list<CharT> init, 
             const Allocator& alloc = Allocator());

Given what stringis an alias for basic_stringchar, the specific signature will be

string(std::initializer_list<char> init, 
       const Allocator& alloc = Allocator());

{1, '*'}, int char, ? , std::initializer_list - ?

Answer 1

{1, '*'}, int, char, ?

1, '*' char . initializer_list<char>. initializer_list . initializer_list , .

-init- , , . , .