std::filesystem::path::root_directory
Min standard notice:
Returns the root directory of the generic-format path. If the path (in generic format) does not include root directory, returns path().
# Declarations
path root_directory() const;
(since C++17)
# Return value
The root directory of the path.
# Example
#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main()
{
fs::path p = fs::current_path();
std::cout << "The current path " << p << " decomposes into:\n"
<< "root name " << p.root_name() << '\n'
<< "root directory " << p.root_directory() << '\n'
<< "relative path " << p.relative_path() << '\n';
}