c++ pushing dereferenced objects to vector - c++

Question

I'm making a function to take in a reference to a path on the filesystem and recursively add file names to a vector. But first I have to be able to add paths to a vector.
what is wrong with this method?
namespace filesys = boost::filesystem;
Method:
void recursive_file_list(filesys::path & root_path, vector<filesys::path> & paths) {
paths->push_back(*root_path); // line 14
// TODO: add more logic to actually recurse through file system
// for now just add root_path (even though root_path is path of directory, not file)
}
And I call it like so:
int main(int argc, char* argv[]) {
// Use the command line arguments
filesys::path abs_path; // line 23
if ( argc > 1 )
// Make the system complete this path to absolute path
abs_path = filesys::system_complete( filesys::path( argv[1] ) );
else {
// If no arguments given
cout << "usage: list_files [path]" << endl;
exit(1);
}
// Is this a valid path?
if (!filesys::exists( abs_path )) {
cout << "The path you have specified does not exist." << endl;
exit(2);
}
// If this is a directory
vector<filesys::path> filepaths();
if (filesys::is_directory( abs_path )) {
cout << "You have specified a directory." << endl;
recursive_file_list(&abs_path, &filepaths);
}
else {
cout << "You have specified a file." << endl;
}
}
Error:
list_files.cpp: In function 'void recursive_file_list(boost::filesystem3::path&, std::vector<boost::filesystem3::path, std::allocator<boost::filesystem3::path> >&)':
list_files.cpp:14: error: base operand of '->' has non-pointer type 'std::vector<boost::filesystem3::path, std::allocator<boost::filesystem3::path> >'
list_files.cpp:14: error: no match for 'operator*' in '*root_path'
list_files.cpp: In function 'int main(int, char**)':
list_files.cpp:43: error: invalid initialization of non-const reference of type 'boost::filesystem3::path&' from a temporary of type 'boost::filesystem3::path*'
list_files.cpp:13: error: in passing argument 1 of 'void recursive_file_list(boost::filesystem3::path&, std::vector<boost::filesystem3::path, std::allocator<boost::filesystem3::path> >&)'
I don't understand - I'm passing it by reference and then dereferencing it to add it...not sure what I'm doing wrong.

Answer 1

You can't dereference references! The * and -> operators do not apply to references; you would push the path itself to the vector itself:
paths.push_back(root_path); // line 14
and furthermore, you don't pass addresses to reference arguments, just the arguments themselves, so you would call the function like this:
recursive_file_list(abs_path, filepaths);
References have pointer-like non-copy semantics all by themselves; you do not need to help them along by taking addresses or trying to dereference them.