ndnboost: Include boost::iostreams for internal use.
diff --git a/include/ndnboost/filesystem/operations.hpp b/include/ndnboost/filesystem/operations.hpp
new file mode 100644
index 0000000..b395e49
--- /dev/null
+++ b/include/ndnboost/filesystem/operations.hpp
@@ -0,0 +1,1096 @@
+//  ndnboost/filesystem/operations.hpp  ---------------------------------------------------//
+
+//  Copyright Beman Dawes 2002-2009
+//  Copyright Jan Langer 2002
+//  Copyright Dietmar Kuehl 2001                                        
+//  Copyright Vladimir Prus 2002
+   
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+//  Library home page: http://www.boost.org/libs/filesystem
+
+//--------------------------------------------------------------------------------------//
+
+#ifndef NDNBOOST_FILESYSTEM3_OPERATIONS_HPP
+#define NDNBOOST_FILESYSTEM3_OPERATIONS_HPP
+
+#include <ndnboost/config.hpp>
+
+# if defined( NDNBOOST_NO_STD_WSTRING )
+#   error Configuration not supported: Boost.Filesystem V3 and later requires std::wstring support
+# endif
+
+#include <ndnboost/filesystem/config.hpp>
+#include <ndnboost/filesystem/path.hpp>
+
+#include <ndnboost/detail/scoped_enum_emulation.hpp>
+#include <ndnboost/detail/bitmask.hpp>
+#include <ndnboost/system/error_code.hpp>
+#include <ndnboost/system/system_error.hpp>
+#include <ndnboost/shared_ptr.hpp>
+#include <ndnboost/utility/enable_if.hpp>
+#include <ndnboost/type_traits/is_same.hpp>
+#include <ndnboost/iterator.hpp>
+#include <ndnboost/cstdint.hpp>
+#include <ndnboost/assert.hpp>
+
+#include <string>
+#include <utility> // for pair
+#include <ctime>
+#include <vector>
+#include <stack>
+
+#ifdef NDNBOOST_WINDOWS_API
+#  include <fstream>
+#endif
+
+#include <ndnboost/config/abi_prefix.hpp> // must be the last #include
+
+//--------------------------------------------------------------------------------------//
+
+namespace ndnboost
+{
+  namespace filesystem
+  {
+
+//--------------------------------------------------------------------------------------//
+//                                     file_type                                        //
+//--------------------------------------------------------------------------------------//
+
+  enum file_type
+  { 
+    status_error,
+#   ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+    status_unknown = status_error,
+#   endif
+    file_not_found,
+    regular_file,
+    directory_file,
+    // the following may not apply to some operating systems or file systems
+    symlink_file,
+    block_file,
+    character_file,
+    fifo_file,
+    socket_file,
+    reparse_file,  // Windows: FILE_ATTRIBUTE_REPARSE_POINT that is not a symlink
+    type_unknown,  // file does exist, but isn't one of the above types or
+                   // we don't have strong enough permission to find its type
+
+    _detail_directory_symlink  // internal use only; never exposed to users
+  };
+
+//--------------------------------------------------------------------------------------//
+//                                       perms                                          //
+//--------------------------------------------------------------------------------------//
+
+  enum perms
+  {
+    no_perms = 0,       // file_not_found is no_perms rather than perms_not_known
+
+    // POSIX equivalent macros given in comments.
+    // Values are from POSIX and are given in octal per the POSIX standard.
+
+    // permission bits
+    
+    owner_read = 0400,  // S_IRUSR, Read permission, owner
+    owner_write = 0200, // S_IWUSR, Write permission, owner
+    owner_exe = 0100,   // S_IXUSR, Execute/search permission, owner
+    owner_all = 0700,   // S_IRWXU, Read, write, execute/search by owner
+
+    group_read = 040,   // S_IRGRP, Read permission, group
+    group_write = 020,  // S_IWGRP, Write permission, group
+    group_exe = 010,    // S_IXGRP, Execute/search permission, group
+    group_all = 070,    // S_IRWXG, Read, write, execute/search by group
+
+    others_read = 04,   // S_IROTH, Read permission, others
+    others_write = 02,  // S_IWOTH, Write permission, others
+    others_exe = 01,    // S_IXOTH, Execute/search permission, others
+    others_all = 07,    // S_IRWXO, Read, write, execute/search by others
+
+    all_all = owner_all|group_all|others_all,  // 0777
+
+    // other POSIX bits
+
+    set_uid_on_exe = 04000, // S_ISUID, Set-user-ID on execution
+    set_gid_on_exe = 02000, // S_ISGID, Set-group-ID on execution
+    sticky_bit     = 01000, // S_ISVTX,
+                            // (POSIX XSI) On directories, restricted deletion flag 
+	                          // (V7) 'sticky bit': save swapped text even after use 
+                            // (SunOS) On non-directories: don't cache this file
+                            // (SVID-v4.2) On directories: restricted deletion flag
+                            // Also see http://en.wikipedia.org/wiki/Sticky_bit
+
+    perms_mask = all_all|set_uid_on_exe|set_gid_on_exe|sticky_bit,  // 07777
+
+    perms_not_known = 0xFFFF, // present when directory_entry cache not loaded
+
+    // options for permissions() function
+
+    add_perms = 0x1000,     // adds the given permission bits to the current bits
+    remove_perms = 0x2000,  // removes the given permission bits from the current bits;
+                            // choose add_perms or remove_perms, not both; if neither add_perms
+                            // nor remove_perms is given, replace the current bits with
+                            // the given bits.
+
+    symlink_perms = 0x4000  // on POSIX, don't resolve symlinks; implied on Windows
+  };
+
+  NDNBOOST_BITMASK(perms)
+
+//--------------------------------------------------------------------------------------//
+//                                    file_status                                       //
+//--------------------------------------------------------------------------------------//
+
+  class NDNBOOST_FILESYSTEM_DECL file_status
+  {
+  public:
+             file_status()            : m_value(status_error), m_perms(perms_not_known) {}
+    explicit file_status(file_type v, perms prms = perms_not_known)
+                                      : m_value(v), m_perms(prms) {}
+
+    // observers
+    file_type  type() const                       { return m_value; }
+    perms      permissions() const                { return m_perms; } 
+
+    // modifiers
+    void       type(file_type v)                  { m_value = v; }
+    void       permissions(perms prms)            { m_perms = prms; }
+
+    bool operator==(const file_status& rhs) const { return type() == rhs.type() && 
+                                                    permissions() == rhs.permissions(); }
+    bool operator!=(const file_status& rhs) const { return !(*this == rhs); }
+
+  private:
+    file_type   m_value;
+    enum perms  m_perms;
+  };
+
+  inline bool type_present(file_status f) { return f.type() != status_error; }
+  inline bool permissions_present(file_status f)
+                                          {return f.permissions() != perms_not_known;}
+  inline bool status_known(file_status f) { return type_present(f) && permissions_present(f); }
+  inline bool exists(file_status f)       { return f.type() != status_error
+                                                && f.type() != file_not_found; }
+  inline bool is_regular_file(file_status f){ return f.type() == regular_file; }
+  inline bool is_directory(file_status f) { return f.type() == directory_file; }
+  inline bool is_symlink(file_status f)   { return f.type() == symlink_file; }
+  inline bool is_other(file_status f)     { return exists(f) && !is_regular_file(f)
+                                                && !is_directory(f) && !is_symlink(f); }
+
+# ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+  inline bool is_regular(file_status f)   { return f.type() == regular_file; }
+# endif
+
+  struct space_info
+  {
+    // all values are byte counts
+    ndnboost::uintmax_t capacity;
+    ndnboost::uintmax_t free;      // <= capacity
+    ndnboost::uintmax_t available; // <= free
+  };
+
+  NDNBOOST_SCOPED_ENUM_START(copy_option)
+    {none, fail_if_exists = none, overwrite_if_exists};
+  NDNBOOST_SCOPED_ENUM_END
+
+//--------------------------------------------------------------------------------------//
+//                             implementation details                                   //
+//--------------------------------------------------------------------------------------//
+
+  namespace detail
+  {
+    NDNBOOST_FILESYSTEM_DECL
+    file_status status(const path&p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    file_status symlink_status(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    bool is_empty(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path initial_path(system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path canonical(const path& p, const path& base, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void copy(const path& from, const path& to, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void copy_directory(const path& from, const path& to, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void copy_file(const path& from, const path& to,
+                    NDNBOOST_SCOPED_ENUM(copy_option) option,  // See ticket #2925
+                    system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void copy_symlink(const path& existing_symlink, const path& new_symlink, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    bool create_directories(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    bool create_directory(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void create_directory_symlink(const path& to, const path& from,
+                                  system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void create_hard_link(const path& to, const path& from, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void create_symlink(const path& to, const path& from, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path current_path(system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void current_path(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    bool equivalent(const path& p1, const path& p2, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    ndnboost::uintmax_t file_size(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    ndnboost::uintmax_t hard_link_count(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    std::time_t last_write_time(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void last_write_time(const path& p, const std::time_t new_time,
+                         system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void permissions(const path& p, perms prms, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path read_symlink(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+      // For standardization, if the committee doesn't like "remove", consider "eliminate"
+    bool remove(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    ndnboost::uintmax_t remove_all(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void rename(const path& old_p, const path& new_p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    void resize_file(const path& p, uintmax_t size, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    space_info space(const path& p, system::error_code* ec=0); 
+    NDNBOOST_FILESYSTEM_DECL
+    path system_complete(const path& p, system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path temp_directory_path(system::error_code* ec=0);
+    NDNBOOST_FILESYSTEM_DECL
+    path unique_path(const path& p, system::error_code* ec=0);
+  }  // namespace detail
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                             status query functions                                   //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+  inline
+  file_status status(const path& p)    {return detail::status(p);}
+  inline 
+  file_status status(const path& p, system::error_code& ec)
+                                       {return detail::status(p, &ec);}
+  inline 
+  file_status symlink_status(const path& p) {return detail::symlink_status(p);}
+  inline
+  file_status symlink_status(const path& p, system::error_code& ec)
+                                       {return detail::symlink_status(p, &ec);}
+  inline 
+  bool exists(const path& p)           {return exists(detail::status(p));}
+  inline 
+  bool exists(const path& p, system::error_code& ec)
+                                       {return exists(detail::status(p, &ec));}
+  inline 
+  bool is_directory(const path& p)     {return is_directory(detail::status(p));}
+  inline 
+  bool is_directory(const path& p, system::error_code& ec)
+                                       {return is_directory(detail::status(p, &ec));}
+  inline 
+  bool is_regular_file(const path& p)  {return is_regular_file(detail::status(p));}
+  inline 
+  bool is_regular_file(const path& p, system::error_code& ec)
+                                       {return is_regular_file(detail::status(p, &ec));}
+  inline 
+  bool is_other(const path& p)         {return is_other(detail::status(p));}
+  inline 
+  bool is_other(const path& p, system::error_code& ec)
+                                       {return is_other(detail::status(p, &ec));}
+  inline
+  bool is_symlink(const path& p)       {return is_symlink(detail::symlink_status(p));}
+  inline 
+  bool is_symlink(const path& p, system::error_code& ec)
+                                       {return is_symlink(detail::symlink_status(p, &ec));}
+# ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+  inline
+  bool is_regular(const path& p)       {return is_regular(detail::status(p));}
+  inline
+  bool is_regular(const path& p, system::error_code& ec)
+                                       {return is_regular(detail::status(p, &ec));}
+# endif
+
+  inline
+  bool is_empty(const path& p)         {return detail::is_empty(p);}
+  inline
+  bool is_empty(const path& p, system::error_code& ec)
+                                       {return detail::is_empty(p, &ec);}
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                             operational functions                                    //
+//                  in alphabetical order, unless otherwise noted                       //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+ 
+  //  forward declarations
+  path current_path();  // fwd declaration
+  path initial_path();
+
+  NDNBOOST_FILESYSTEM_DECL
+  path absolute(const path& p, const path& base=current_path());
+  //  If base.is_absolute(), throws nothing. Thus no need for ec argument
+
+  inline
+  path canonical(const path& p, const path& base=current_path())
+                                       {return detail::canonical(p, base);}
+  inline
+  path canonical(const path& p, system::error_code& ec)
+                                       {return detail::canonical(p, current_path(), &ec);}
+  inline
+  path canonical(const path& p, const path& base, system::error_code& ec)
+                                       {return detail::canonical(p, base, &ec);}
+
+# ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+  inline
+  path complete(const path& p)
+  {
+    return absolute(p, initial_path());
+  }
+
+  inline
+  path complete(const path& p, const path& base)
+  {
+    return absolute(p, base);
+  }
+# endif
+
+  inline
+  void copy(const path& from, const path& to) {detail::copy(from, to);}
+
+  inline
+  void copy(const path& from, const path& to, system::error_code& ec) 
+                                       {detail::copy(from, to, &ec);}
+  inline
+  void copy_directory(const path& from, const path& to)
+                                       {detail::copy_directory(from, to);}
+  inline
+  void copy_directory(const path& from, const path& to, system::error_code& ec)
+                                       {detail::copy_directory(from, to, &ec);}
+  inline
+  void copy_file(const path& from, const path& to,   // See ticket #2925
+                 NDNBOOST_SCOPED_ENUM(copy_option) option)
+                                       {detail::copy_file(from, to, option);}
+  inline
+  void copy_file(const path& from, const path& to)
+                                       {detail::copy_file(from, to, copy_option::fail_if_exists);}
+  inline
+  void copy_file(const path& from, const path& to,   // See ticket #2925
+                 NDNBOOST_SCOPED_ENUM(copy_option) option, system::error_code& ec)
+                                       {detail::copy_file(from, to, option, &ec);}
+  inline
+  void copy_file(const path& from, const path& to, system::error_code& ec)
+                                       {detail::copy_file(from, to, copy_option::fail_if_exists, &ec);}
+  inline
+  void copy_symlink(const path& existing_symlink, const path& new_symlink) {detail::copy_symlink(existing_symlink, new_symlink);}
+
+  inline
+  void copy_symlink(const path& existing_symlink, const path& new_symlink, system::error_code& ec)
+                                       {detail::copy_symlink(existing_symlink, new_symlink, &ec);}
+  inline
+  bool create_directories(const path& p) {return detail::create_directories(p);}
+
+  inline
+  bool create_directories(const path& p, system::error_code& ec)
+                                       {return detail::create_directories(p, &ec);}
+  inline
+  bool create_directory(const path& p) {return detail::create_directory(p);}
+
+  inline
+  bool create_directory(const path& p, system::error_code& ec)
+                                       {return detail::create_directory(p, &ec);}
+  inline
+  void create_directory_symlink(const path& to, const path& from)
+                                       {detail::create_directory_symlink(to, from);}
+  inline
+  void create_directory_symlink(const path& to, const path& from, system::error_code& ec)
+                                       {detail::create_directory_symlink(to, from, &ec);}
+  inline
+  void create_hard_link(const path& to, const path& new_hard_link) {detail::create_hard_link(to, new_hard_link);}
+
+  inline
+  void create_hard_link(const path& to, const path& new_hard_link, system::error_code& ec)
+                                       {detail::create_hard_link(to, new_hard_link, &ec);}
+  inline
+  void create_symlink(const path& to, const path& new_symlink) {detail::create_symlink(to, new_symlink);}
+
+  inline
+  void create_symlink(const path& to, const path& new_symlink, system::error_code& ec)
+                                       {detail::create_symlink(to, new_symlink, &ec);}
+  inline
+  path current_path()                  {return detail::current_path();}
+
+  inline
+  path current_path(system::error_code& ec) {return detail::current_path(&ec);}
+
+  inline
+  void current_path(const path& p)     {detail::current_path(p);}
+
+  inline
+  void current_path(const path& p, system::error_code& ec) {detail::current_path(p, &ec);}
+
+  inline
+  bool equivalent(const path& p1, const path& p2) {return detail::equivalent(p1, p2);}
+
+  inline
+  bool equivalent(const path& p1, const path& p2, system::error_code& ec)
+                                       {return detail::equivalent(p1, p2, &ec);}
+  inline
+  ndnboost::uintmax_t file_size(const path& p) {return detail::file_size(p);}
+
+  inline
+  ndnboost::uintmax_t file_size(const path& p, system::error_code& ec)
+                                       {return detail::file_size(p, &ec);}
+  inline
+  ndnboost::uintmax_t hard_link_count(const path& p) {return detail::hard_link_count(p);}
+
+  inline
+  ndnboost::uintmax_t hard_link_count(const path& p, system::error_code& ec)
+                                       {return detail::hard_link_count(p, &ec);}
+  inline
+  path initial_path()                  {return detail::initial_path();}
+
+  inline
+  path initial_path(system::error_code& ec) {return detail::initial_path(&ec);}
+
+  template <class Path>
+  path initial_path() {return initial_path();}
+  template <class Path>
+  path initial_path(system::error_code& ec) {return detail::initial_path(&ec);}
+
+  inline
+  std::time_t last_write_time(const path& p) {return detail::last_write_time(p);}
+
+  inline
+  std::time_t last_write_time(const path& p, system::error_code& ec)
+                                       {return detail::last_write_time(p, &ec);}
+  inline
+  void last_write_time(const path& p, const std::time_t new_time)
+                                       {detail::last_write_time(p, new_time);}
+  inline
+  void last_write_time(const path& p, const std::time_t new_time, system::error_code& ec)
+                                       {detail::last_write_time(p, new_time, &ec);}
+  inline
+  void permissions(const path& p, perms prms)
+                                       {detail::permissions(p, prms);}
+  inline
+  void permissions(const path& p, perms prms, system::error_code& ec)
+                                       {detail::permissions(p, prms, &ec);}
+
+  inline
+  path read_symlink(const path& p)     {return detail::read_symlink(p);}
+
+  inline
+  path read_symlink(const path& p, system::error_code& ec)
+                                       {return detail::read_symlink(p, &ec);}
+  inline
+    // For standardization, if the committee doesn't like "remove", consider "eliminate"
+  bool remove(const path& p)           {return detail::remove(p);}
+
+  inline
+  bool remove(const path& p, system::error_code& ec) {return detail::remove(p, &ec);}
+
+  inline
+  ndnboost::uintmax_t remove_all(const path& p) {return detail::remove_all(p);}
+    
+  inline
+  ndnboost::uintmax_t remove_all(const path& p, system::error_code& ec)
+                                       {return detail::remove_all(p, &ec);}
+  inline
+  void rename(const path& old_p, const path& new_p) {detail::rename(old_p, new_p);}
+
+  inline
+  void rename(const path& old_p, const path& new_p, system::error_code& ec)
+                                       {detail::rename(old_p, new_p, &ec);}
+  inline  // name suggested by Scott McMurray
+  void resize_file(const path& p, uintmax_t size) {detail::resize_file(p, size);}
+
+  inline
+  void resize_file(const path& p, uintmax_t size, system::error_code& ec)
+                                       {detail::resize_file(p, size, &ec);}
+  inline
+  space_info space(const path& p)      {return detail::space(p);} 
+
+  inline
+  space_info space(const path& p, system::error_code& ec) {return detail::space(p, &ec);} 
+
+# ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+  inline bool symbolic_link_exists(const path& p)
+                                       { return is_symlink(symlink_status(p)); }
+# endif
+
+  inline
+  path system_complete(const path& p)  {return detail::system_complete(p);}
+
+  inline
+  path system_complete(const path& p, system::error_code& ec)
+                                       {return detail::system_complete(p, &ec);}
+  inline
+  path temp_directory_path()           {return detail::temp_directory_path();}
+
+  inline
+  path temp_directory_path(system::error_code& ec) 
+                                       {return detail::temp_directory_path(&ec);}
+  inline
+  path unique_path(const path& p="%%%%-%%%%-%%%%-%%%%")
+                                       { return detail::unique_path(p); }
+  inline
+  path unique_path(const path& p, system::error_code& ec)
+                                       { return detail::unique_path(p, &ec); }
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                                 directory_entry                                      //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+//  GCC has a problem with a member function named path within a namespace or 
+//  sub-namespace that also has a class named path. The workaround is to always
+//  fully qualify the name path when it refers to the class name.
+
+class NDNBOOST_FILESYSTEM_DECL directory_entry
+{
+public:
+
+  // compiler generated copy constructor, copy assignment, and destructor apply
+
+  directory_entry() {}
+  explicit directory_entry(const ndnboost::filesystem::path& p,
+    file_status st = file_status(), file_status symlink_st=file_status())
+    : m_path(p), m_status(st), m_symlink_status(symlink_st)
+    {}
+
+  void assign(const ndnboost::filesystem::path& p,
+    file_status st = file_status(), file_status symlink_st = file_status())
+    { m_path = p; m_status = st; m_symlink_status = symlink_st; }
+
+  void replace_filename(const ndnboost::filesystem::path& p,
+    file_status st = file_status(), file_status symlink_st = file_status())
+  {
+    m_path.remove_filename();
+    m_path /= p;
+    m_status = st;
+    m_symlink_status = symlink_st;
+  }
+
+# ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+  void replace_leaf(const ndnboost::filesystem::path& p,
+    file_status st, file_status symlink_st)
+      { replace_filename(p, st, symlink_st); }
+# endif
+
+  const ndnboost::filesystem::path&  path() const               {return m_path;}
+  file_status   status() const                               {return m_get_status();}
+  file_status   status(system::error_code& ec) const         {return m_get_status(&ec);}
+  file_status   symlink_status() const                       {return m_get_symlink_status();}
+  file_status   symlink_status(system::error_code& ec) const {return m_get_symlink_status(&ec);}
+
+  bool operator==(const directory_entry& rhs) {return m_path == rhs.m_path;} 
+  bool operator!=(const directory_entry& rhs) {return m_path != rhs.m_path;} 
+  bool operator< (const directory_entry& rhs) {return m_path < rhs.m_path;} 
+  bool operator<=(const directory_entry& rhs) {return m_path <= rhs.m_path;} 
+  bool operator> (const directory_entry& rhs) {return m_path > rhs.m_path;} 
+  bool operator>=(const directory_entry& rhs) {return m_path >= rhs.m_path;} 
+
+private:
+  ndnboost::filesystem::path   m_path;
+  mutable file_status       m_status;           // stat()-like
+  mutable file_status       m_symlink_status;   // lstat()-like
+
+  file_status m_get_status(system::error_code* ec=0) const;
+  file_status m_get_symlink_status(system::error_code* ec=0) const;
+}; // directory_entry
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                            directory_iterator helpers                                //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+class directory_iterator;
+
+namespace detail
+{
+  NDNBOOST_FILESYSTEM_DECL
+    system::error_code dir_itr_close(// never throws()
+    void *& handle
+#   if     defined(NDNBOOST_POSIX_API)
+    , void *& buffer
+#   endif
+  ); 
+
+  struct dir_itr_imp
+  {
+    directory_entry  dir_entry;
+    void*            handle;
+
+#   ifdef NDNBOOST_POSIX_API
+    void*            buffer;  // see dir_itr_increment implementation
+#   endif
+
+    dir_itr_imp() : handle(0)
+#   ifdef NDNBOOST_POSIX_API
+      , buffer(0)
+#   endif
+    {}
+
+    ~dir_itr_imp() // never throws
+    {
+      dir_itr_close(handle
+#       if defined(NDNBOOST_POSIX_API)
+         , buffer
+#       endif
+    );
+    }
+  };
+
+  // see path::iterator: comment below
+  NDNBOOST_FILESYSTEM_DECL void directory_iterator_construct(directory_iterator& it,
+    const path& p, system::error_code* ec);
+  NDNBOOST_FILESYSTEM_DECL void directory_iterator_increment(directory_iterator& it,
+    system::error_code* ec);
+
+}  // namespace detail
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                                directory_iterator                                    //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+  class directory_iterator
+    : public ndnboost::iterator_facade< directory_iterator,
+                                     directory_entry,
+                                     ndnboost::single_pass_traversal_tag >
+  {
+  public:
+
+    directory_iterator(){}  // creates the "end" iterator
+
+    // iterator_facade derived classes don't seem to like implementations in
+    // separate translation unit dll's, so forward to detail functions
+    explicit directory_iterator(const path& p)
+        : m_imp(new detail::dir_itr_imp)
+          { detail::directory_iterator_construct(*this, p, 0); }
+
+    directory_iterator(const path& p, system::error_code& ec)
+        : m_imp(new detail::dir_itr_imp)
+          { detail::directory_iterator_construct(*this, p, &ec); }
+
+   ~directory_iterator() {} // never throws
+
+    directory_iterator& increment(system::error_code& ec)
+    { 
+      detail::directory_iterator_increment(*this, &ec);
+      return *this;
+    }
+
+  private:
+    friend struct detail::dir_itr_imp;
+    friend NDNBOOST_FILESYSTEM_DECL void detail::directory_iterator_construct(directory_iterator& it,
+      const path& p, system::error_code* ec);
+    friend NDNBOOST_FILESYSTEM_DECL void detail::directory_iterator_increment(directory_iterator& it,
+      system::error_code* ec);
+
+    // shared_ptr provides shallow-copy semantics required for InputIterators.
+    // m_imp.get()==0 indicates the end iterator.
+    ndnboost::shared_ptr< detail::dir_itr_imp >  m_imp;
+
+    friend class ndnboost::iterator_core_access;
+
+    ndnboost::iterator_facade<
+      directory_iterator,
+      directory_entry,
+      ndnboost::single_pass_traversal_tag >::reference dereference() const 
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(), "attempt to dereference end iterator");
+      return m_imp->dir_entry;
+    }
+
+    void increment() { detail::directory_iterator_increment(*this, 0); }
+
+    bool equal(const directory_iterator& rhs) const
+      { return m_imp == rhs.m_imp; }
+  };
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                      recursive_directory_iterator helpers                            //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+  NDNBOOST_SCOPED_ENUM_START(symlink_option)
+  {
+    none,
+    no_recurse = none,         // don't follow directory symlinks (default behavior)
+    recurse,                   // follow directory symlinks
+    _detail_no_push = recurse << 1  // internal use only
+  };
+  NDNBOOST_SCOPED_ENUM_END
+
+  NDNBOOST_BITMASK(NDNBOOST_SCOPED_ENUM(symlink_option))
+
+  namespace detail
+  {
+    struct recur_dir_itr_imp
+    {
+      typedef directory_iterator element_type;
+      std::stack< element_type, std::vector< element_type > > m_stack;
+      int  m_level;
+      NDNBOOST_SCOPED_ENUM(symlink_option) m_options;
+
+      recur_dir_itr_imp() : m_level(0), m_options(symlink_option::none) {}
+
+      void increment(system::error_code* ec);  // ec == 0 means throw on error
+
+      void pop();
+
+    };
+
+    //  Implementation is inline to avoid dynamic linking difficulties with m_stack:
+    //  Microsoft warning C4251, m_stack needs to have dll-interface to be used by
+    //  clients of struct 'ndnboost::filesystem::detail::recur_dir_itr_imp'
+
+    inline
+    void recur_dir_itr_imp::increment(system::error_code* ec)
+    // ec == 0 means throw on error
+    {
+      if ((m_options & symlink_option::_detail_no_push) == symlink_option::_detail_no_push)
+        m_options &= ~symlink_option::_detail_no_push;
+
+      else
+      {
+        // Logic for following predicate was contributed by Daniel Aarno to handle cyclic
+        // symlinks correctly and efficiently, fixing ticket #5652.
+        //   if (((m_options & symlink_option::recurse) == symlink_option::recurse
+        //         || !is_symlink(m_stack.top()->symlink_status()))
+        //       && is_directory(m_stack.top()->status())) ...
+        // The predicate code has since been rewritten to pass error_code arguments,
+        // per ticket #5653.
+        bool or_pred = (m_options & symlink_option::recurse) == symlink_option::recurse
+                       || (ec == 0 ? !is_symlink(m_stack.top()->symlink_status())
+                                   : !is_symlink(m_stack.top()->symlink_status(*ec)));
+        if (ec != 0 && *ec)
+          return;
+        bool and_pred = or_pred && (ec == 0 ? is_directory(m_stack.top()->status())
+                                            : is_directory(m_stack.top()->status(*ec)));
+        if (ec != 0 && *ec)
+          return;
+
+        if (and_pred)
+        {
+          if (ec == 0)
+            m_stack.push(directory_iterator(m_stack.top()->path()));
+          else
+          {
+            m_stack.push(directory_iterator(m_stack.top()->path(), *ec));
+            if (*ec)
+              return;
+          }
+          if (m_stack.top() != directory_iterator())
+          {
+            ++m_level;
+            return;
+          }
+          m_stack.pop();
+        }
+      }
+
+      while (!m_stack.empty() && ++m_stack.top() == directory_iterator())
+      {
+        m_stack.pop();
+        --m_level;
+      }
+    }
+
+    inline
+    void recur_dir_itr_imp::pop()
+    {
+      NDNBOOST_ASSERT_MSG(m_level > 0,
+        "pop() on recursive_directory_iterator with level < 1");
+
+      do
+      {
+        m_stack.pop();
+        --m_level;
+      }
+      while (!m_stack.empty() && ++m_stack.top() == directory_iterator());
+    }
+  } // namespace detail
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                           recursive_directory_iterator                               //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+
+  class recursive_directory_iterator
+    : public ndnboost::iterator_facade<
+        recursive_directory_iterator,
+        directory_entry,
+        ndnboost::single_pass_traversal_tag >
+  {
+  public:
+
+    recursive_directory_iterator(){}  // creates the "end" iterator
+
+    explicit recursive_directory_iterator(const path& dir_path,
+      NDNBOOST_SCOPED_ENUM(symlink_option) opt = symlink_option::none)
+      : m_imp(new detail::recur_dir_itr_imp)
+    {
+      m_imp->m_options = opt;
+      m_imp->m_stack.push(directory_iterator(dir_path));
+      if (m_imp->m_stack.top() == directory_iterator())
+        { m_imp.reset (); }
+    }
+
+    recursive_directory_iterator(const path& dir_path,
+      NDNBOOST_SCOPED_ENUM(symlink_option) opt,
+      system::error_code & ec)
+    : m_imp(new detail::recur_dir_itr_imp)
+    {
+      m_imp->m_options = opt;
+      m_imp->m_stack.push(directory_iterator(dir_path, ec));
+      if (m_imp->m_stack.top() == directory_iterator())
+        { m_imp.reset (); }
+    }
+
+    recursive_directory_iterator(const path& dir_path,
+      system::error_code & ec)
+    : m_imp(new detail::recur_dir_itr_imp)
+    {
+      m_imp->m_options = symlink_option::none;
+      m_imp->m_stack.push(directory_iterator(dir_path, ec));
+      if (m_imp->m_stack.top() == directory_iterator())
+        { m_imp.reset (); }
+    }
+
+    recursive_directory_iterator& increment(system::error_code& ec)
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "increment() on end recursive_directory_iterator");
+      m_imp->increment(&ec);
+      if (m_imp->m_stack.empty())
+        m_imp.reset(); // done, so make end iterator
+      return *this;
+    }
+
+    int level() const
+    { 
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "level() on end recursive_directory_iterator");
+      return m_imp->m_level;
+    }
+
+    bool no_push_pending() const
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "is_no_push_requested() on end recursive_directory_iterator");
+      return (m_imp->m_options & symlink_option::_detail_no_push)
+        == symlink_option::_detail_no_push;
+    }
+
+#   ifndef NDNBOOST_FILESYSTEM_NO_DEPRECATED
+    bool no_push_request() const { return no_push_pending(); }
+#   endif
+
+    void pop()
+    { 
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "pop() on end recursive_directory_iterator");
+      m_imp->pop();
+      if (m_imp->m_stack.empty()) m_imp.reset(); // done, so make end iterator
+    }
+
+    void no_push(bool value=true)
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "no_push() on end recursive_directory_iterator");
+      if (value)
+        m_imp->m_options |= symlink_option::_detail_no_push;
+      else
+        m_imp->m_options &= ~symlink_option::_detail_no_push;
+    }
+
+    file_status status() const
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "status() on end recursive_directory_iterator");
+      return m_imp->m_stack.top()->status();
+    }
+
+    file_status symlink_status() const
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "symlink_status() on end recursive_directory_iterator");
+      return m_imp->m_stack.top()->symlink_status();
+    }
+
+  private:
+
+    // shared_ptr provides shallow-copy semantics required for InputIterators.
+    // m_imp.get()==0 indicates the end iterator.
+    ndnboost::shared_ptr< detail::recur_dir_itr_imp >  m_imp;
+
+    friend class ndnboost::iterator_core_access;
+
+    ndnboost::iterator_facade< 
+      recursive_directory_iterator,
+      directory_entry,
+      ndnboost::single_pass_traversal_tag >::reference
+    dereference() const 
+    {
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "dereference of end recursive_directory_iterator");
+      return *m_imp->m_stack.top();
+    }
+
+    void increment()
+    { 
+      NDNBOOST_ASSERT_MSG(m_imp.get(),
+        "increment of end recursive_directory_iterator");
+      m_imp->increment(0);
+      if (m_imp->m_stack.empty())
+        m_imp.reset(); // done, so make end iterator
+    }
+
+    bool equal(const recursive_directory_iterator& rhs) const
+      { return m_imp == rhs.m_imp; }
+
+  };
+
+# if !defined(NDNBOOST_FILESYSTEM_NO_DEPRECATED)
+  typedef recursive_directory_iterator wrecursive_directory_iterator;
+# endif
+
+//--------------------------------------------------------------------------------------//
+//                                                                                      //
+//                            class filesystem_error                                    //
+//                                                                                      //
+//--------------------------------------------------------------------------------------//
+  
+  class NDNBOOST_SYMBOL_VISIBLE filesystem_error : public system::system_error
+  {
+  // see http://www.boost.org/more/error_handling.html for design rationale
+
+  // all functions are inline to avoid issues with crossing dll boundaries
+
+  public:
+    // compiler generates copy constructor and copy assignment
+
+    filesystem_error(
+      const std::string & what_arg, system::error_code ec)
+      : system::system_error(ec, what_arg)
+    {
+      try
+      {
+        m_imp_ptr.reset(new m_imp);
+      }
+      catch (...) { m_imp_ptr.reset(); }
+    }
+
+    filesystem_error(
+      const std::string & what_arg, const path& path1_arg,
+      system::error_code ec)
+      : system::system_error(ec, what_arg)
+    {
+      try
+      {
+        m_imp_ptr.reset(new m_imp);
+        m_imp_ptr->m_path1 = path1_arg;
+      }
+      catch (...) { m_imp_ptr.reset(); }
+    }
+    
+    filesystem_error(
+      const std::string & what_arg, const path& path1_arg,
+      const path& path2_arg, system::error_code ec)
+      : system::system_error(ec, what_arg)
+    {
+      try
+      {
+        m_imp_ptr.reset(new m_imp);
+        m_imp_ptr->m_path1 = path1_arg;
+        m_imp_ptr->m_path2 = path2_arg;
+      }
+      catch (...) { m_imp_ptr.reset(); }
+    }
+
+    ~filesystem_error() throw() {}
+
+    const path& path1() const
+    {
+      static const path empty_path;
+      return m_imp_ptr.get() ? m_imp_ptr->m_path1 : empty_path ;
+    }
+    const path& path2() const
+    {
+      static const path empty_path;
+      return m_imp_ptr.get() ? m_imp_ptr->m_path2 : empty_path ;
+    }
+
+    const char* what() const throw()
+    {
+      if (!m_imp_ptr.get())
+        return system::system_error::what();
+
+      try
+      {
+        if (m_imp_ptr->m_what.empty())
+        {
+          m_imp_ptr->m_what = system::system_error::what();
+          if (!m_imp_ptr->m_path1.empty())
+          {
+            m_imp_ptr->m_what += ": \"";
+            m_imp_ptr->m_what += m_imp_ptr->m_path1.string();
+            m_imp_ptr->m_what += "\"";
+          }
+          if (!m_imp_ptr->m_path2.empty())
+          {
+            m_imp_ptr->m_what += ", \"";
+            m_imp_ptr->m_what += m_imp_ptr->m_path2.string();
+            m_imp_ptr->m_what += "\"";
+          }
+        }
+        return m_imp_ptr->m_what.c_str();
+      }
+      catch (...)
+      {
+        return system::system_error::what();
+      }
+    }
+
+  private:
+    struct m_imp
+    {
+      path         m_path1; // may be empty()
+      path         m_path2; // may be empty()
+      std::string  m_what;  // not built until needed
+    };
+    ndnboost::shared_ptr<m_imp> m_imp_ptr;
+  };
+
+//  test helper  -----------------------------------------------------------------------//
+
+//  Not part of the documented interface since false positives are possible;
+//  there is no law that says that an OS that has large stat.st_size
+//  actually supports large file sizes.
+
+  namespace detail
+  {
+    NDNBOOST_FILESYSTEM_DECL bool possible_large_file_size_support();
+  }
+
+  } // namespace filesystem
+} // namespace ndnboost
+
+#include <ndnboost/config/abi_suffix.hpp> // pops abi_prefix.hpp pragmas
+#endif // NDNBOOST_FILESYSTEM3_OPERATIONS_HPP