//  boost/filesystem/path.hpp  -----------------------------------------------//

//  Copyright Beman Dawes 2002-2005

//  Use, modification, and distribution is subject to the Boost Software

//  License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

//  http://www.boost.org/LICENSE_1_0.txt)

//  See library home page at http://www.boost.org/libs/filesystem

//----------------------------------------------------------------------------// 

#ifndef BOOST_FILESYSTEM_PATH_HPP

#define BOOST_FILESYSTEM_PATH_HPP

#include <boost/filesystem/config.hpp>

#include <boost/iterator/iterator_facade.hpp>

#include <boost/throw_exception.hpp>

#include <boost/shared_ptr.hpp>

#include <boost/type_traits/is_same.hpp>

#include <boost/static_assert.hpp>

#include <string>

#include <algorithm> // for lexicographical_compare

#include <iosfwd>    // needed by basic_path inserter and extractor

#include <stdexcept>

#include <cassert>

# ifndef BOOST_FILESYSTEM_NARROW_ONLY

#   include <locale>

# endif

#include <boost/config/abi_prefix.hpp> // must be the last #include

//----------------------------------------------------------------------------//

namespace boost

{

  namespace BOOST_FILESYSTEM_NAMESPACE

  {

    template<class String, class Traits> class basic_path;

    struct path_traits;

    typedef basic_path< std::string, path_traits > path;

    struct path_traits

    {

      typedef std::string internal_string_type;

      typedef std::string external_string_type;

      static external_string_type to_external( const path &,

        const internal_string_type & src ) { return src; }

      static internal_string_type to_internal(

        const external_string_type & src ) { return src; }

    };

# ifndef BOOST_FILESYSTEM_NARROW_ONLY

    struct wpath_traits;

    typedef basic_path< std::wstring, wpath_traits > wpath;

    struct wpath_traits

    {

      typedef std::wstring internal_string_type;

# ifdef BOOST_WINDOWS_API

      typedef std::wstring external_string_type;

      static external_string_type to_external( const wpath &,

        const internal_string_type & src ) { return src; }

      static internal_string_type to_internal(

        const external_string_type & src ) { return src; }

# else

      typedef std::string external_string_type;

      static external_string_type to_external( const wpath & ph,

        const internal_string_type & src );

      static internal_string_type to_internal(

        const external_string_type & src );

# endif

      static void imbue( const std::locale & loc );

      static bool imbue( const std::locale & loc, const std::nothrow_t & );

    };

# endif // ifndef BOOST_FILESYSTEM_NARROW_ONLY

//  error reporting support  -------------------------------------------------//

    typedef int errno_type;  // determined by C standard

# ifdef BOOST_WINDOWS_API

    typedef unsigned system_error_type;

    BOOST_FILESYSTEM_DECL

    errno_type lookup_errno( system_error_type sys_err_code );

# else

    typedef int system_error_type;

    inline errno_type lookup_errno( system_error_type sys_err_code )

      { return sys_err_code; }

# endif

    // deprecated support for legacy function name

    inline errno_type lookup_error_code( system_error_type sys_err_code )

      { return lookup_errno( sys_err_code ); }

    BOOST_FILESYSTEM_DECL

    void system_message( system_error_type sys_err_code, std::string & target );

    // Effects: appends error message to target

# if defined(BOOST_WINDOWS_API) && !defined(BOOST_FILESYSTEM_NARROW_ONLY)

    BOOST_FILESYSTEM_DECL void

    system_message( system_error_type sys_err_code, std::wstring & target );

# endif

    //  filesystem_error  ----------------------------------------------------//

    class filesystem_error : public std::runtime_error

    // see http://www.boost.org/more/error_handling.html for design rationale

    {

    public:

      filesystem_error()

        : std::runtime_error("filesystem error"), m_sys_err(0) {}

      explicit filesystem_error(

        const std::string & what_arg, system_error_type sys_ec = 0 )

        : std::runtime_error(what_arg), m_sys_err(sys_ec) {}

      system_error_type  system_error() const { return m_sys_err; }

      // Note: system_error() == 0 implies a library (rather than system) error

    private:

      system_error_type m_sys_err;

    };

    //  basic_filesystem_error  ----------------------------------------------//

    template<class Path>

    class basic_filesystem_error : public filesystem_error

    {

    // see http://www.boost.org/more/error_handling.html for design rationale

    public:

      // compiler generates copy constructor and copy assignment

      typedef Path path_type;

      basic_filesystem_error( const std::string & what,

        system_error_type sys_err_code );

      basic_filesystem_error( const std::string & what,

        const path_type & path1, system_error_type sys_err_code );

      basic_filesystem_error( const std::string & what, const path_type & path1,

        const path_type & path2, system_error_type sys_err_code );

      ~basic_filesystem_error() throw() {}

      const path_type & path1() const

      {

        static const path_type empty_path;

        return m_imp_ptr.get() ? m_imp_ptr->m_path1 : empty_path ;

      }

      const path_type & path2() const

      {

        static const path_type empty_path;

        return m_imp_ptr.get() ? m_imp_ptr->m_path2 : empty_path ;

      }

    private:

      struct m_imp

      {

        path_type       m_path1; // may be empty()

        path_type       m_path2; // may be empty()

      };

      boost::shared_ptr<m_imp> m_imp_ptr;

    };

    typedef basic_filesystem_error<path> filesystem_path_error;

# ifndef BOOST_FILESYSTEM_NARROW_ONLY

    typedef basic_filesystem_error<wpath> filesystem_wpath_error;

# endif

    //  path traits  ---------------------------------------------------------//

    template<class Path> struct is_basic_path

      { BOOST_STATIC_CONSTANT( bool, value = false ); };

    template<> struct is_basic_path<path>

      { BOOST_STATIC_CONSTANT( bool, value = true ); };

# ifndef BOOST_FILESYSTEM_NARROW_ONLY

    template<> struct is_basic_path<wpath>

      { BOOST_STATIC_CONSTANT( bool, value = true ); };

# endif

    // these only have to be specialized if Path::string_type::value_type

    // is not convertible from char

    template<class Path> struct slash

      { BOOST_STATIC_CONSTANT( char, value = '/' ); };

    template<class Path> struct dot

      { BOOST_STATIC_CONSTANT( char, value = '.' ); };

    template<class Path> struct colon

      { BOOST_STATIC_CONSTANT( char, value = ':' ); };

# ifdef BOOST_WINDOWS_PATH

    template<class Path> struct path_alt_separator

      { BOOST_STATIC_CONSTANT( char, value = '\\' ); };

# endif

    //  workaround for VC++ 7.0 and earlier issues with nested classes

    namespace detail

    {

      template<class Path>

      class iterator_helper

      {

      public:

        typedef typename Path::iterator iterator;

        static void do_increment( iterator & ph );

        static void do_decrement( iterator & ph );

      };

    }

    //  basic_path  ----------------------------------------------------------//

    template<class String, class Traits>

    class basic_path

    {

    // invariant: m_path valid according to the portable generic path grammar

      // validate template arguments

// TODO: get these working

//      BOOST_STATIC_ASSERT( ::boost::is_same<String,typename Traits::internal_string_type>::value );

//      BOOST_STATIC_ASSERT( ::boost::is_same<typename Traits::external_string_type,std::string>::value || ::boost::is_same<typename Traits::external_string_type,std::wstring>::value );

    public:

      // compiler generates copy constructor and copy assignment

      typedef basic_path<String, Traits> path_type;

      typedef String string_type;

      typedef typename String::value_type value_type;

      typedef Traits traits_type;

      typedef typename Traits::external_string_type external_string_type; 

      // constructors/destructor

      basic_path() {}

      basic_path( const string_type & s ) { operator/=( s ); }

      basic_path( const value_type * s )  { operator/=( s ); }

#     ifndef BOOST_NO_MEMBER_TEMPLATES

        template <class InputIterator>

          basic_path( InputIterator first, InputIterator last )

            { append( first, last ); }

#     endif

     ~basic_path() {}

      // assignments

      basic_path & operator=( const string_type & s )

      {

#     if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, >= 310)

        m_path.clear();

#     else

        m_path.erase( m_path.begin(), m_path.end() );

#     endif

        operator/=( s ); 

        return *this;

      }

      basic_path & operator=( const value_type * s )

      { 

#     if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, >= 310)

        m_path.clear();

#     else

        m_path.erase( m_path.begin(), m_path.end() );

#     endif

        operator/=( s ); 

        return *this;

      }

#     ifndef BOOST_NO_MEMBER_TEMPLATES

        template <class InputIterator>

          basic_path & assign( InputIterator first, InputIterator last )

            { m_path.clear(); append( first, last ); return *this; }

#     endif

      // modifiers

      basic_path & operator/=( const basic_path & rhs )  { return operator /=( rhs.string().c_str() ); }

      basic_path & operator/=( const string_type & rhs ) { return operator /=( rhs.c_str() ); }

      basic_path & operator/=( const value_type * s );

#     ifndef BOOST_NO_MEMBER_TEMPLATES

        template <class InputIterator>

          basic_path & append( InputIterator first, InputIterator last );

#     endif

      void swap( basic_path & rhs )

      {

        m_path.swap( rhs.m_path );

#       ifdef BOOST_CYGWIN_PATH

          std::swap( m_cygwin_root, rhs.m_cygwin_root );

#       endif

      }

      basic_path & remove_leaf();

      // observers

      const string_type & string() const         { return m_path; }

      const string_type file_string() const;

      const string_type directory_string() const { return file_string(); }

      const external_string_type external_file_string() const { return Traits::to_external( *this, file_string() ); }

      const external_string_type external_directory_string() const { return Traits::to_external( *this, directory_string() ); }

      basic_path   root_path() const;

      string_type  root_name() const;

      string_type  root_directory() const;

      basic_path   relative_path() const;

      string_type  leaf() const;

      basic_path   branch_path() const;

      bool empty() const               { return m_path.empty(); } // name consistent with std containers

      bool is_complete() const;

      bool has_root_path() const;

      bool has_root_name() const;

      bool has_root_directory() const;

      bool has_relative_path() const   { return !relative_path().empty(); }

      bool has_leaf() const            { return !m_path.empty(); }

      bool has_branch_path() const     { return !branch_path().empty(); }

      // iterators

      class iterator : public boost::iterator_facade<

        iterator,

        string_type const,

        boost::bidirectional_traversal_tag >

      {

      private:

        friend class boost::iterator_core_access;

        friend class boost::BOOST_FILESYSTEM_NAMESPACE::basic_path<String, Traits>;

        const string_type & dereference() const

          { return m_name; }

        bool equal( const iterator & rhs ) const

          { return m_path_ptr == rhs.m_path_ptr && m_pos == rhs.m_pos; }

        friend class boost::BOOST_FILESYSTEM_NAMESPACE::detail::iterator_helper<path_type>;

        void increment()

        { 

          boost::BOOST_FILESYSTEM_NAMESPACE::detail::iterator_helper<path_type>::do_increment(

            *this );

        }

        void decrement()

        { 

          boost::BOOST_FILESYSTEM_NAMESPACE::detail::iterator_helper<path_type>::do_decrement(

            *this );

        }

        string_type             m_name;     // current element

        const basic_path *      m_path_ptr; // path being iterated over

        typename string_type::size_type  m_pos;  // position of name in

                                            // path_ptr->string(). The

                                            // end() iterator is indicated by 

                                            // pos == path_ptr->m_path.size()

      }; // iterator

      typedef iterator const_iterator;

      iterator begin() const;

      iterator end() const;

    private:

      // Note: This is an implementation for POSIX and Windows, where there

      // are only minor differences between generic and native path grammars.

      // Private members might be quite different in other implementations,

      // particularly where there were wide differences between portable and

      // native path formats, or between file_string() and

      // directory_string() formats, or simply that the implementation

      // was willing expend additional memory to achieve greater speed for

      // some operations at the expense of other operations.

      string_type  m_path; // invariant: portable path grammar

                           // on Windows, backslashes converted to slashes

#   ifdef BOOST_CYGWIN_PATH

      bool m_cygwin_root; // if present, m_path[0] was slash. note: initialization

                          // done by append

#   endif  

      void m_append_separator_if_needed();

      void m_append( value_type value ); // converts Windows alt_separator

      // Was qualified; como433beta8 reports:

      //    warning #427-D: qualified name is not allowed in member declaration 

      friend class iterator;

      friend class boost::BOOST_FILESYSTEM_NAMESPACE::detail::iterator_helper<path_type>;

      // Deprecated features ease transition for existing code. Don't use these

      // in new code.

# ifndef BOOST_FILESYSTEM_NO_DEPRECATED

    public:

      typedef bool (*name_check)( const std::string & name );

      basic_path( const string_type & str, name_check ) { operator/=( str ); }

      basic_path( const typename string_type::value_type * s, name_check )

        { operator/=( s );}

      string_type native_file_string() const { return file_string(); }

      string_type native_directory_string() const { return directory_string(); }

      static bool default_name_check_writable() { return false; } 

      static void default_name_check( name_check ) {}

      static name_check default_name_check() { return 0; }

      basic_path & canonize();

      basic_path & normalize();

# endif

    };

  //  basic_path non-member functions  ---------------------------------------//

    template< class String, class Traits >

    inline void swap( basic_path<String, Traits> & lhs,

               basic_path<String, Traits> & rhs ) { lhs.swap( rhs ); }

    template< class String, class Traits >

    bool operator<( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs )

    {

      return std::lexicographical_compare(

        lhs.begin(), lhs.end(), rhs.begin(), rhs.end() );

    }

    template< class String, class Traits >

    bool operator<( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs )

    {

      basic_path<String, Traits> tmp( lhs );

      return std::lexicographical_compare(

        tmp.begin(), tmp.end(), rhs.begin(), rhs.end() );

    }

    template< class String, class Traits >

    bool operator<( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs )

    {

      basic_path<String, Traits> tmp( lhs );

      return std::lexicographical_compare(

        tmp.begin(), tmp.end(), rhs.begin(), rhs.end() );

    }

    template< class String, class Traits >

    bool operator<( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

    {

      basic_path<String, Traits> tmp( rhs );

      return std::lexicographical_compare(

        lhs.begin(), lhs.end(), tmp.begin(), tmp.end() );

    }

    template< class String, class Traits >

    bool operator<( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

    {

      basic_path<String, Traits> tmp( rhs );

      return std::lexicographical_compare(

        lhs.begin(), lhs.end(), tmp.begin(), tmp.end() );

    }

    template< class String, class Traits >

    inline bool operator==( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs )

    { 

      return !(lhs < rhs) && !(rhs < lhs);

    }

    template< class String, class Traits >

    inline bool operator==( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs )

    {

      basic_path<String, Traits> tmp( lhs );

      return !(tmp < rhs) && !(rhs < tmp);

    }

    template< class String, class Traits >

    inline bool operator==( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs )

    {

      basic_path<String, Traits> tmp( lhs );

      return !(tmp < rhs) && !(rhs < tmp);

    }

    template< class String, class Traits >

    inline bool operator==( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

    {

      basic_path<String, Traits> tmp( rhs );

      return !(lhs < tmp) && !(tmp < lhs);

    }

    template< class String, class Traits >

    inline bool operator==( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

    {

      basic_path<String, Traits> tmp( rhs );

      return !(lhs < tmp) && !(tmp < lhs);

    }

    template< class String, class Traits >

    inline bool operator!=( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs ) { return !(lhs == rhs); }

    template< class String, class Traits >

    inline bool operator!=( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs ) { return !(basic_path<String, Traits>(lhs) == rhs); }

    template< class String, class Traits >

    inline bool operator!=( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs ) { return !(basic_path<String, Traits>(lhs) == rhs); }

    template< class String, class Traits >

    inline bool operator!=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

                    { return !(lhs == basic_path<String, Traits>(rhs)); }

    template< class String, class Traits >

    inline bool operator!=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

                    { return !(lhs == basic_path<String, Traits>(rhs)); }

    template< class String, class Traits >

    inline bool operator>( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs ) { return rhs < lhs; }

    template< class String, class Traits >

    inline bool operator>( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs ) { return rhs < basic_path<String, Traits>(lhs); }

    template< class String, class Traits >

    inline bool operator>( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs ) { return rhs < basic_path<String, Traits>(lhs); }

    template< class String, class Traits >

    inline bool operator>( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

                    { return basic_path<String, Traits>(rhs) < lhs; }

    template< class String, class Traits >

    inline bool operator>( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

                    { return basic_path<String, Traits>(rhs) < lhs; }

    template< class String, class Traits >

    inline bool operator<=( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs ) { return !(rhs < lhs); }

    template< class String, class Traits >

    inline bool operator<=( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs ) { return !(rhs < basic_path<String, Traits>(lhs)); }

    template< class String, class Traits >

    inline bool operator<=( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs ) { return !(rhs < basic_path<String, Traits>(lhs)); }

    template< class String, class Traits >

    inline bool operator<=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

                    { return !(basic_path<String, Traits>(rhs) < lhs); }

    template< class String, class Traits >

    inline bool operator<=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

                    { return !(basic_path<String, Traits>(rhs) < lhs); }

    template< class String, class Traits >

    inline bool operator>=( const basic_path<String, Traits> & lhs, const basic_path<String, Traits> & rhs ) { return !(lhs < rhs); }

    template< class String, class Traits >

    inline bool operator>=( const typename basic_path<String, Traits>::string_type::value_type * lhs,

                    const basic_path<String, Traits> & rhs ) { return !(lhs < basic_path<String, Traits>(rhs)); }

    template< class String, class Traits >

    inline bool operator>=( const typename basic_path<String, Traits>::string_type & lhs,

                    const basic_path<String, Traits> & rhs ) { return !(lhs < basic_path<String, Traits>(rhs)); }

    template< class String, class Traits >

    inline bool operator>=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type::value_type * rhs )

                    { return !(basic_path<String, Traits>(lhs) < rhs); }

    template< class String, class Traits >

    inline bool operator>=( const basic_path<String, Traits> & lhs,

                    const typename basic_path<String, Traits>::string_type & rhs )

                    { return !(basic_path<String, Traits>(lhs) < rhs); }

    // operator /

    template< class String, class Traits >

    inline basic_path<String, Traits> operator/( 

      const basic_path<String, Traits> & lhs,

      const basic_path<String, Traits> & rhs )

      { return basic_path<String, Traits>( lhs ) /= rhs; }

    template< class String, class Traits >

    inline basic_path<String, Traits> operator/( 

      const basic_path<String, Traits> & lhs,

      const typename String::value_type * rhs )

      { return basic_path<String, Traits>( lhs ) /=

          basic_path<String, Traits>( rhs ); }

    template< class String, class Traits >

    inline basic_path<String, Traits> operator/( 

      const basic_path<String, Traits> & lhs, const String & rhs )

      { return basic_path<String, Traits>( lhs ) /=

          basic_path<String, Traits>( rhs ); }

    template< class String, class Traits >

    inline basic_path<String, Traits> operator/( 

      const typename String::value_type * lhs,

      const basic_path<String, Traits> & rhs )

      { return basic_path<String, Traits>( lhs ) /= rhs; }

    template< class String, class Traits >

    inline basic_path<String, Traits> operator/(

      const String & lhs, const basic_path<String, Traits> & rhs )

      { return basic_path<String, Traits>( lhs ) /= rhs; }

    //  inserters and extractors  --------------------------------------------//

// bypass VC++ 7.0 and earlier, and broken Borland compilers

# if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) && !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

    template< class Path >

    std::basic_ostream< typename Path::string_type::value_type,

      typename Path::string_type::traits_type > &

      operator<<

      ( std::basic_ostream< typename Path::string_type::value_type,

      typename Path::string_type::traits_type >& os, const Path & ph )

    {

      os << ph.string();

      return os;

    }

    template< class Path >

    std::basic_istream< typename Path::string_type::value_type,

      typename Path::string_type::traits_type > &

      operator>>

      ( std::basic_istream< typename Path::string_type::value_type,

      typename Path::string_type::traits_type >& is, Path & ph )

    {

      typename Path::string_type str;

      is >> str;

      ph = str;

      return is;

    }

# elif BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

    template< class String, class Traits >

    std::basic_ostream< BOOST_DEDUCED_TYPENAME String::value_type,

      BOOST_DEDUCED_TYPENAME String::traits_type > &

      operator<<

      ( std::basic_ostream< BOOST_DEDUCED_TYPENAME String::value_type,

          BOOST_DEDUCED_TYPENAME String::traits_type >& os, 

        const basic_path< String, Traits > & ph )

    {

      os << ph.string();

      return os;

    }

    template< class String, class Traits >

    std::basic_istream< BOOST_DEDUCED_TYPENAME String::value_type, 

      BOOST_DEDUCED_TYPENAME String::traits_type > &

      operator>>

      ( std::basic_istream< BOOST_DEDUCED_TYPENAME String::value_type,

          BOOST_DEDUCED_TYPENAME String::traits_type> & is,

        basic_path< String, Traits > & ph )

    {

      String str;

      is >> str;

      ph = str;

      return is;

    }

# endif

  //  path::name_checks  -----------------------------------------------------//

    BOOST_FILESYSTEM_DECL bool portable_posix_name( const std::string & name );

    BOOST_FILESYSTEM_DECL bool windows_name( const std::string & name );

    BOOST_FILESYSTEM_DECL bool portable_name( const std::string & name );

    BOOST_FILESYSTEM_DECL bool portable_directory_name( const std::string & name );

    BOOST_FILESYSTEM_DECL bool portable_file_name( const std::string & name );

    BOOST_FILESYSTEM_DECL bool native( const std::string & name );

    inline bool no_check( const std::string & )

      { return true; }

// implementation  -----------------------------------------------------------//

    namespace detail

    {

      //  is_separator helper ------------------------------------------------//

      template<class Path>

      inline  bool is_separator( typename Path::string_type::value_type c )

      {

        return c == slash<Path>::value

#     ifdef BOOST_WINDOWS_PATH

          || c == path_alt_separator<Path>::value

#     endif

          ;

      }

      // leaf_pos helper  ----------------------------------------------------//

      template<class String, class Traits>

      typename String::size_type leaf_pos(

        const String & str, // precondition: portable generic path grammar

        typename String::size_type end_pos ) // end_pos is past-the-end position

      // return 0 if str itself is leaf (or empty)

      {

        typedef typename

          boost::BOOST_FILESYSTEM_NAMESPACE::basic_path<String, Traits> path_type;

        // case: "//"

        if ( end_pos == 2 

          && str[0] == slash<path_type>::value

          && str[1] == slash<path_type>::value ) return 0;

        // case: ends in "/"

        if ( end_pos && str[end_pos-1] == slash<path_type>::value )

          return end_pos-1;

        // set pos to start of last element

        typename String::size_type pos(

          str.find_last_of( slash<path_type>::value, end_pos-1 ) );

#       ifdef BOOST_WINDOWS_PATH

        if ( pos == String::npos )

          pos = str.find_last_of( path_alt_separator<path_type>::value, end_pos-1 );

        if ( pos == String::npos )

          pos = str.find_last_of( colon<path_type>::value, end_pos-2 );

#       endif

        return ( pos == String::npos // path itself must be a leaf (or empty)

          || (pos == 1 && str[0] == slash<path_type>::value) ) // or net

            ? 0 // so leaf is entire string

            : pos + 1; // or starts after delimiter

      }

      // first_element helper  -----------------------------------------------//

      //   sets pos and len of first element, excluding extra separators

      //   if src.empty(), sets pos,len, to 0,0.

      template<class String, class Traits>

        void first_element(

          const String & src, // precondition: portable generic path grammar

          typename String::size_type & element_pos,

          typename String::size_type & element_size,

#       if !BOOST_WORKAROUND( BOOST_MSVC, <= 1310 ) // VC++ 7.1

          typename String::size_type size = String::npos

#       else

          typename String::size_type size = -1

#       endif

          )

      {

        if ( size == String::npos ) size = src.size();

        element_pos = 0;

        element_size = 0;

        if ( src.empty() ) return;

        typedef typename boost::BOOST_FILESYSTEM_NAMESPACE::basic_path<String, Traits> path_type;

        typename String::size_type cur(0);

        // deal with // [network]

        if ( size >= 2 && src[0] == slash<path_type>::value

          && src[1] == slash<path_type>::value

          && (size == 2

            || src[2] != slash<path_type>::value) )

        { 

          cur += 2;

          element_size += 2;

        }

        // leading (not non-network) separator

        else if ( src[0] == slash<path_type>::value )

        {

          ++element_size;

          // bypass extra leading separators

          while ( cur+1 < size

            && src[cur+1] == slash<path_type>::value )

          {

            ++cur;

            ++element_pos;

          }

          return;

        }

        // at this point, we have either a plain name, a network name,

        // or (on Windows only) a device name

        // find the end

        while ( cur < size

#         ifdef BOOST_WINDOWS_PATH

          && src[cur] != colon<path_type>::value

#         endif

          && src[cur] != slash<path_type>::value )

        {

          ++cur;

          ++element_size;

        }

#       ifdef BOOST_WINDOWS_PATH

        if ( cur == size ) return;

        // include device delimiter

        if ( src[cur] == colon<path_type>::value )

          { ++element_size; }

#       endif

        return;

      }

      // root_directory_start helper  ----------------------------------------//

      template<class String, class Traits>

      typename String::size_type root_directory_start(

        const String & s, // precondition: portable generic path grammar

        typename String::size_type size )

      // return npos if no root_directory found

      {

        typedef typename boost::BOOST_FILESYSTEM_NAMESPACE::basic_path<String, Traits> path_type;

#     ifdef BOOST_WINDOWS_PATH

        // case "c:/"

        if ( size > 2

          && s[1] == colon<path_type>::value

          && s[2] == slash<path_type>::value ) return 2;

#     endif

        // case "//"

        if ( size == 2

          && s[0] == slash<path_type>::value

          && s[1] == slash<path_type>::value ) return String::npos;

        // case "//net {/}"

        if ( size > 3

          && s[0] == slash<path_type>::value

          && s[1] == slash<path_type>::value

          && s[2] != slash<path_type>::value )

        {

          typename String::size_type pos(

            s.find( slash<path_type>::value, 2 ) );

          return pos < size ? pos : String::npos;

        }

        // case "/"

        if ( size > 0 && s[0] == slash<path_type>::value ) return 0;

        return String::npos;

      }

      // is_non_root_slash helper  -------------------------------------------//

      template<class String, class Traits>

      bool is_non_root_slash( const String & str,

        typename String::size_type pos ) // pos is position of the slash

      {

        typedef typename

          boost::BOOST_FILESYSTEM_NAMESPACE::basic_path<String, Traits>

            path_type;

        assert( !str.empty() && str[pos] == slash<path_type>::value

          && "precondition violation" );

        // subsequent logic expects pos to be for leftmost slash of a set

        while ( pos > 0 && str[pos-1] == slash<path_type>::value )

          --pos;

        return  pos != 0

          && (pos <= 2 || str[1] != slash<path_type>::value

            || str.find( slash<path_type>::value, 2 ) != pos)

#       ifdef BOOST_WINDOWS_PATH

          && (pos !=2 || str[1] != colon<path_type>::value)

#       endif

            ;

      }

    } // namespace detail

    // decomposition functions  ----------------------------------------------//

    template<class String, class Traits>

    String basic_path<String, Traits>::leaf() const

    {

      typename String::size_type end_pos(

        detail::leaf_pos<String, Traits>( m_path, m_path.size() ) );

      return (m_path.size()

                && end_pos

                && m_path[end_pos] == slash<path_type>::value

                && detail::is_non_root_slash< String, Traits >(m_path, end_pos))

        ? String( 1, dot<path_type>::value )

        : m_path.substr( end_pos );

    }

    template<class String, class Traits>

    basic_path<String, Traits> basic_path<String, Traits>::branch_path() const

    {

      typename String::size_type end_pos(

        detail::leaf_pos<String, Traits>( m_path, m_path.size() ) );

      bool leaf_was_separator( m_path.size()

        && m_path[end_pos] == slash<path_type>::value );

      // skip separators unless root directory

      typename string_type::size_type root_dir_pos( detail::root_directory_start

        <string_type, traits_type>( m_path, end_pos ) );

      for ( ; 

        end_pos > 0

        && (end_pos-1) != root_dir_pos

        && m_path[end_pos-1] == slash<path_type>::value

        ;

        --end_pos ) {}

     return (end_pos == 1 && root_dir_pos == 0 && leaf_was_separator)

       ? path_type()

       : path_type( m_path.substr( 0, end_pos ) );

    }

    template<class String, class Traits>

    basic_path<String, Traits> basic_path<String, Traits>::relative_path() const

    {

      iterator itr( begin() );

      for ( ; itr.m_pos != m_path.size()

          && (itr.m_name[0] == slash<path_type>::value

#     ifdef BOOST_WINDOWS_PATH

          || itr.m_name[itr.m_name.size()-1]

            == colon<path_type>::value

#     endif

             ); ++itr ) {}

      return basic_path<String, Traits>( m_path.substr( itr.m_pos ) );

    }

    template<class String, class Traits>

    String basic_path<String, Traits>::root_name() const

    {

      iterator itr( begin() );

      return ( itr.m_pos != m_path.size()

        && (

            ( itr.m_name.size() > 1

              && itr.m_name[0] == slash<path_type>::value

              && itr.m_name[1] == slash<path_type>::value

            )

#     ifdef BOOST_WINDOWS_PATH

          || itr.m_name[itr.m_name.size()-1]

            == colon<path_type>::value

#     endif

           ) )

        ? *itr

        : String();

    }

    template<class String, class Traits>

    String basic_path<String, Traits>::root_directory() const

    {

      typename string_type::size_type start(

        detail::root_directory_start<String, Traits>( m_path, m_path.size() ) );

      return start == string_type::npos

        ? string_type()

        : m_path.substr( start, 1 );

    }

    template<class String, class Traits>

    basic_path<String, Traits> basic_path<String, Traits>::root_path() const

    {

      // even on POSIX, root_name() is non-empty() on network paths

      return basic_path<String, Traits>( root_name() ) /= root_directory();

    }

    // path query functions  -------------------------------------------------//

    template<class String, class Traits>

    inline bool basic_path<String, Traits>::is_complete() const

    {

#   ifdef BOOST_WINDOWS_PATH

      return has_root_name() && has_root_directory();

#   else

      return has_root_directory();

#   endif

    }

    template<class String, class Traits>

    inline bool basic_path<String, Traits>::has_root_path() const

    {

      return !root_path().empty();

    }

    template<class String, class Traits>

    inline bool basic_path<String, Traits>::has_root_name() const

    {

      return !root_name().empty();

    }

    template<class String, class Traits>

    inline bool basic_path<String, Traits>::has_root_directory() const

    {

      return !root_directory().empty();

    }

    // append  ---------------------------------------------------------------//

    template<class String, class Traits>

    void basic_path<String, Traits>::m_append_separator_if_needed()

    // requires: !empty()

    {