#pragma once
///@file

#include <optional>

#include "types.hh"

namespace nix {

/**
 * Save the current mount namespace. Ignored if called more than
 * once.
 */
void saveMountNamespace();

/**
 * Restore the mount namespace saved by saveMountNamespace(). Ignored
 * if saveMountNamespace() was never called.
 */
void restoreMountNamespace();

/**
 * Cause this thread to not share any FS attributes with the main
 * thread, because this causes setns() in restoreMountNamespace() to
 * fail.
 */
void unshareFilesystem();

#if __linux__

bool userNamespacesSupported();

bool mountAndPidNamespacesSupported();

#endif

}