Передача std::bind в функцию

#include <iostream>
#include <vector>
#include <string>
#include <functional>
 
void find_files(
    const std::string& absolute_path,
    const std::function<bool(const std::string& filename)> predicate,
    std::vector<std::string>& out_files);
 
 
int main() {
  std::cout << "Hello World!" << std::endl;
  auto is_needle_extension = [](const std::string& filename, const std::vector<std::string>& needle_extensions) -> bool {
   return false;
  };
 
  std::vector<std::string> headers;
  find_files("root_folder", [&](const std::string& filename) {
    return is_needle_extension(filename, {".h", ".hpp"});
  }, headers);
 
  auto is_needle = [](const std::string& filename) -> bool { return true; };
  find_files("root_folder", is_needle, headers);
 
 
  using std::placeholders::_1;
  //find_files("root_folder", std::bind(is_needle_extension, _1, {".h", ".hpp"}), headers);
 
 
 
  return 0;
}
 
void find_files(
    const std::string& absolute_path,
    const std::function<bool(const std::string& filename)> predicate,
    std::vector<std::string>& out_files) {
 
  const std::string filename = "1.txt";
  if (predicate(filename)) {
    out_files.emplace_back(filename);
  }
}

std::bind(is_needle_extension, _1, std::vector<std::string>{".h", ".hpp"})

#include <iostream>
#include <vector>
#include <string>
#include <functional>
 
void find_files(
    const std::string& absolute_path,
    const std::function<bool( const std::string& filename )> predicate,
    std::vector<std::string>& out_files )
{
 
    const std::string filename = "1.txt";
    if( predicate( filename ) )
    {
        out_files.emplace_back( filename );
    }
}
 
 
int main()
{
    auto is_needle_extension = 
        []( const std::string& filename, const std::vector<std::string>& needle_extensions )
    {
        return false;
    };
 
    std::vector<std::string> out;
    find_files( "root_folder", std::bind( is_needle_extension, std::string("mySpecialFileName.txt"), {".h", ".hpp"} ), out );
 
 
 
    return 0;
}

    find_files("root_folder", [&is_needle_extension](const std::string &s) {
        return is_needle_extension(s, {".h", ".hpp"});
    },headers);

using namespace std::placeholders;
find_files("root_folder", std::bind(is_needle_extension, _1, std::vector<std::string>{".h", ".hpp"}), out);

int main()
{
    auto is_needle_extension =
            []( const std::string& filename, const std::vector<std::string>& needle_extensions ) -> bool
            {
                std::cout << filename;
                return false;
            };
 
    using namespace std::placeholders;
 
    auto b = std::bind(is_needle_extension, _1, std::vector<std::string>{".h", ".hpp"});
    const std::function<bool (const std::string& filename)> predicate = b;
    b("Hello");
    predicate("Hello 2");

std::bind(is_needle_extension, _1, std::vector<std::string>{".h", ".hpp"})

std::vector<std::string>{".h", ".hpp"}