/*

 * Copyright (c) 2003

 * Francois Dumont

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */

#ifndef _STLP_STRING_SUM_H

#define _STLP_STRING_SUM_H

_STLP_BEGIN_NAMESPACE

_STLP_MOVE_TO_PRIV_NAMESPACE

/*char wrapper to simulate basic_string*/

template <class _CharT>

struct __char_wrapper {

  typedef const _CharT& const_reference;

  __char_wrapper(_CharT __val) : _Val(__val) {}

  _CharT getValue() const { return _Val; }

  size_t size() const { return 1; }

  const_reference operator[] (size_t __n) const {

    //To avoid a check on __n we use this strange implementation

    return (&_Val)[__n];

  }

private:

  _CharT _Val;

};

/*C string wrapper to simulate basic_string*/

template <class _CharT>

struct __cstr_wrapper {

  typedef const _CharT& const_reference;

  __cstr_wrapper(const _CharT *__cstr, size_t __size) :

    _CStr(__cstr), _Size(__size) {}

  const _CharT* c_str() const { return _CStr; }

  size_t size() const { return _Size; }

  const_reference operator[] (size_t __n) const { return _CStr[__n]; }

private:

  const _CharT *_CStr;

  size_t _Size;

};

/*basic_string wrapper to ensure that we only store a reference to the original string and not copy it*/

template <class _CharT, class _Traits, class _Alloc>

struct __bstr_wrapper {

  typedef const _CharT& const_reference;

  typedef basic_string<_CharT, _Traits, _Alloc> _BString;

  __bstr_wrapper (_BString const& __s) :

    _BStr(__s) {}

  size_t size() const { return _BStr.size(); }

  const_reference operator[] (size_t __n) const { return _BStr[__n]; }

  _BString const& b_str() const { return _BStr; }

private:

  _BString const& _BStr;

};

struct __on_left {};

struct __on_right {};

template <class _CharT, class _Traits, class _Alloc,

          class _Left, class _Right,

          class _StorageDirection>

class __bstr_sum {

public:

  typedef basic_string<_CharT, _Traits, _Alloc> _BString;

  typedef typename _BString::const_reference const_reference;

  typedef typename _BString::const_iterator const_iterator;

  typedef typename _BString::const_reverse_iterator const_reverse_iterator;

  typedef typename _BString::size_type size_type;

  typedef typename _BString::allocator_type allocator_type;

  typedef __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDirection> _Self;

  __bstr_sum (_Left const& lhs, _Right const& rhs) :

    _lhs(lhs), _rhs(rhs) {}

  _Left const& getLhs() const { return _lhs; }

  _Right const& getRhs() const { return _rhs; }

  allocator_type get_allocator() const { return _M_get_storage(false).get_allocator(); }

  const_iterator begin() const { return _M_get_storage().begin(); }

  const_iterator end()   const { return _M_get_storage().end(); }

  const_reverse_iterator rbegin() const { return _M_get_storage().rbegin(); }

  const_reverse_iterator rend()   const { return _M_get_storage().rend(); }

  size_type size() const { return _lhs.size() + _rhs.size(); }

  size_type length() const { return size(); }

  size_t max_size() const { return _M_get_storage().max_size(); }

  size_type capacity() const { return size(); }

  bool empty() const { return size() == 0; }

  const_reference operator[](size_t __n) const

  { return (__n < _lhs.size())?_lhs[__n]:_rhs[__n - _lhs.size()]; }

  const_reference at(size_type __n) const

  { return _M_get_storage().at(__n); }

  //operator +=

  typedef __bstr_sum<_CharT, _Traits, _Alloc, _Self, __bstr_wrapper<_CharT, _Traits, _Alloc>, __on_left> _BStrOnLeft;

  _BStrOnLeft operator += (const _BString& __s) { return append(__s); }

  typedef __bstr_sum<_CharT, _Traits, _Alloc, _Self, __cstr_wrapper<_CharT>, __on_left> _CStrOnLeft;

  _CStrOnLeft operator += (const _CharT* __s) { return append(__s); }

  typedef __bstr_sum<_CharT, _Traits, _Alloc, _Self, __char_wrapper<_CharT>, __on_left> _CharOnLeft;

  _CharOnLeft operator += (_CharT __c) { return _CharOnLeft(*this, __c); }

  //append

  _BStrOnLeft append (const _BString& __s)

  { return _BStrOnLeft(*this, __s); }

  _BString& append(const _BString& __s, size_type __pos, size_type __n)

  { return _M_get_storage().append(__s, __pos, __n); }

  _CStrOnLeft append(const _CharT* __s) {

    const size_type __n = _Traits::length(__s);

    return _CStrOnLeft(*this, __cstr_wrapper<_CharT>(__s, __n));

  }

  _CStrOnLeft append(const _CharT* __s, size_type __n)

  { return _CStrOnLeft(*this, __cstr_wrapper<_CharT>(__s, __n)); }

  _BString& append(size_type __n, _CharT __c)

  {return _M_get_storage().append(__n, __c);}

  template <class _InputIter>

  _BString& append(_InputIter __first, _InputIter __last)

  {return _M_get_storage().append(__first, __last);}

  //assign

  _BString& assign(const _BString& __s) {return _M_get_storage().assign(__s);}

  _BString& assign(const _BString& __s, size_type __pos, size_type __n) {return _M_get_storage().assign(__s, __pos, __n);}

  _BString& assign(const _CharT* __s, size_type __n) {return _M_get_storage().assign(__s, __n);}

  _BString& assign(const _CharT* __s) {return _M_get_storage().assign(__s); }

  _BString& assign(size_type __n, _CharT __c) {return _M_get_storage().assign(__n, __c);}

  //insert

  _BString& insert(size_type __pos, const _BString& __s) {return _M_get_storage().insert(__pos, __s);}

  _BString& insert(size_type __pos, const _BString& __s, size_type __beg, size_type __n)

  {return _M_get_storage().insert(__pos, __s, __beg, __n);}

  _BString& insert(size_type __pos, const _CharT* __s, size_type __n) {return _M_get_storage().insert(__pos, __s, __n);}

  _BString& insert(size_type __pos, const _CharT* __s) {return _M_get_storage().insert(__pos, __s);}

  _BString& insert(size_type __pos, size_type __n, _CharT __c) {return _M_get_storage().insert(__pos, __n, __c);}

  //erase

  _BString& erase(size_type __pos = 0, size_type __n =_BString::npos) {return _M_get_storage().erase(__pos, __n);}

  //replace

  _BString& replace(size_type __pos, size_type __n, const _BString& __s)

  {return _M_get_storage().replace(__pos, __n, __s);}

  _BString& replace(size_type __pos1, size_type __n1, const _BString& __s, size_type __pos2, size_type __n2)

  {return _M_get_storage().replace(__pos1, __n1, __s, __pos2, __n2);}

  _BString& replace(size_type __pos, size_type __n1, const _CharT* __s, size_type __n2)

  {return _M_get_storage().replace(__pos, __n1, __s, __n2);}

  _BString& replace(size_type __pos, size_type __n1, const _CharT* __s)

  {return _M_get_storage().replace(__pos, __n1, __s);}

  _BString& replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)

  {return _M_get_storage().replace(__pos, __n1, __n2, __c);}

  size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const

  {return _M_get_storage().copy(__s, __n, __pos);}

  void swap(_BString& __s)

  {_M_get_storage().swap(__s);}

  const _CharT* c_str() const { return _M_get_storage().c_str(); }

  const _CharT* data()  const { return _M_get_storage().data(); }

  //find family

  size_type find(const _BString& __s, size_type __pos = 0) const { return _M_get_storage().find(__s, __pos); }

  size_type find(const _CharT* __s, size_type __pos = 0) const { return _M_get_storage().find(__s, __pos); }

  size_type find(const _CharT* __s, size_type __pos, size_type __n) const { return _M_get_storage().find(__s, __pos, __n); }

  size_type find(_CharT __c, size_type __pos = 0) const { return _M_get_storage().find(__c, __pos); }

  size_type rfind(const _BString& __s, size_type __pos = _BString::npos) const { return _M_get_storage().rfind(__s, __pos); }

  size_type rfind(const _CharT* __s, size_type __pos = _BString::npos) const { return _M_get_storage().rfind(__s, __pos); }

  size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const { return _M_get_storage().rfind(__s, __pos, __n); }

  size_type rfind(_CharT __c, size_type __pos = _BString::npos) const { return _M_get_storage().rfind(__c, __pos); }

  size_type find_first_of(const _BString& __s, size_type __pos = 0) const

  { return _M_get_storage().find_first_of(__s, __pos); }

  size_type find_first_of(const _CharT* __s, size_type __pos = 0) const

  { return _M_get_storage().find_first_of(__s, __pos); }

  size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const

  { return _M_get_storage().find_first_of(__s, __pos, __n); }

  size_type find_first_of(_CharT __c, size_type __pos = 0) const

  { return _M_get_storage().find(__c, __pos); }

  size_type find_last_of(const _BString& __s, size_type __pos = _BString::npos) const

  { return _M_get_storage().find_last_of(__s, __pos); }

  size_type find_last_of(const _CharT* __s, size_type __pos = _BString::npos) const

  { return _M_get_storage().find_last_of(__s, __pos); }

  size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const

  { return _M_get_storage().find_last_of(__s, __pos, __n); }

  size_type find_last_of(_CharT __c, size_type __pos = _BString::npos) const

  { return _M_get_storage().rfind(__c, __pos); }

  size_type find_first_not_of(const _BString& __s, size_type __pos = 0) const

  { return _M_get_storage().find_first_not_of(__s, __pos); }

  size_type find_first_not_of(const _CharT* __s, size_type __pos = 0) const

  { return _M_get_storage().find_first_not_of(__s, __pos); }

  size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const

  { return _M_get_storage().find_first_not_of(__s, __pos, __n); }

  size_type find_first_not_of(_CharT __c, size_type __pos = 0) const

  { return _M_get_storage().find_first_not_of(__c, __pos); }

  size_type find_last_not_of(const _BString& __s, size_type __pos = _BString::npos) const

  { return _M_get_storage().find_last_not_of(__s, __pos); }

  size_type find_last_not_of(const _CharT* __s, size_type __pos =_BString:: npos) const

  { return _M_get_storage().find_last_not_of(__s, __pos); }

  size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const

  { return _M_get_storage().find_last_not_of(__s, __pos, __n); }

  size_type find_last_not_of(_CharT __c, size_type __pos = _BString::npos) const

  { return _M_get_storage().find_last_not_of(__c, __pos); }

  _BString substr(size_type __pos = 0, size_type __n = _BString::npos) const

  { return _M_get_storage().substr(__pos, __n); }

  //compare

  int compare(const _BString& __s) const

  { return _M_get_storage().compare(__s); }

  int compare(size_type __pos1, size_type __n1, const _Self& __s) const

  { return _M_get_storage().compare(__pos1, __n1, __s); }

  int compare(size_type __pos1, size_type __n1, const _Self& __s, size_type __pos2, size_type __n2) const

  { return _M_get_storage().compare(__pos1, __n1, __s, __pos2, __n2); }

  int compare(const _CharT* __s) const

  { return _M_get_storage().compare(__s); }

  int compare(size_type __pos1, size_type __n1, const _CharT* __s) const

  { return _M_get_storage().compare(__pos1, __n1, __s); }

  int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const

  { return _M_get_storage().compare(__pos1, __n1, __s, __n2); }

  //Returns the underlying basic_string representation of the template expression

  //The non const method will always initialise it.

  _BString& _M_get_storage()

  { return _rhs._M_get_storage(*this, _StorageDirection()); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref,

                           __on_left const& /*StorageDir*/)

  { return _lhs._M_get_storage(__ref); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref,

                           __on_right const& /*StorageDir*/)

  { return _rhs._M_get_storage(__ref); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref)

  { return _M_get_storage(__ref, _StorageDirection()); }

  //The const method can be invoked without initialising the basic_string so avoiding dynamic allocation.

  _BString const& _M_get_storage(bool __do_init = true) const

  { return _M_get_storage(*this, __do_init, _StorageDirection()); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString const& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref,

                                 bool __do_init, __on_left const& /*StorageDir*/) const

  { return _lhs._M_get_storage(__ref, __do_init); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString const& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref,

                                 bool __do_init, __on_right const& /*StorageDir*/) const

  { return _rhs._M_get_storage(__ref, __do_init); }

  template <class _Lhs, class _Rhs, class _StorageDir>

  _BString const& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Lhs, _Rhs, _StorageDir>  const& __ref,

                                 bool __do_init) const

  { return _M_get_storage(__ref, __do_init, _StorageDirection()); }

private:

  _Left  _lhs;

  _Right _rhs;

};

/*

 * For this operator we choose to use the right part as the storage part

 */

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline __bstr_sum<_CharT, _Traits, _Alloc,

                  __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1>,

                  __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2>,

                  __on_right> _STLP_CALL

operator + (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

            const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs) {

  return __bstr_sum<_CharT, _Traits, _Alloc,

                    __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1>,

                    __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2>,

                    __on_right>(__lhs, __rhs);

}

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator == (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

             const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return (__lhs.size() == __rhs.size()) && (__lhs._M_get_storage() == __rhs._M_get_storage()); }

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator < (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

            const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return __lhs._M_get_storage() < __rhs._M_get_storage(); }

#ifdef _STLP_USE_SEPARATE_RELOPS_NAMESPACE

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator != (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

             const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return !(__lhs == __rhs); }

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator > (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

            const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return __rhs < __lhs; }

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator <= (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

             const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return !(__rhs < __lhs); }

template <class _CharT, class _Traits, class _Alloc,

          class _Lh1, class _Rh1, class _StoreDir1,

          class _Lh2, class _Rh2, class _StoreDir2>

inline bool _STLP_CALL

operator >= (const __bstr_sum<_CharT, _Traits, _Alloc, _Lh1, _Rh1, _StoreDir1> &__lhs,

             const __bstr_sum<_CharT, _Traits, _Alloc, _Lh2, _Rh2, _StoreDir2> &__rhs)

{ return !(__lhs < __rhs); }

#endif /* _STLP_USE_SEPARATE_RELOPS_NAMESPACE */

/*

 * This class will be used to simulate a temporary string that is required for

 * a call to the c_str method on the __bstr_sum class.

 */

template <class _CharT, class _Traits, class _Alloc>

struct __sum_storage_elem {

  typedef basic_string<_CharT, _Traits, _Alloc> _BString;

  __sum_storage_elem(_Alloc __alloc) : _M_init(false), _M_storage(__alloc)

  {}

  template <class _Left, class _Right, class _StorageDir>

  void _M_Init(__bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir>  const& __ref) const {

    if (!_M_init) {

      _M_storage = __ref;

      _M_init = true;

    }

  }

  template <class _Left, class _Right, class _StorageDir>

  _BString const& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir>  const& __ref,

                                 bool __do_init) const {

    if (__do_init) {

      _M_Init(__ref);

    }

    return _M_storage;

  }

  template <class _Left, class _Right, class _StorageDir>

  _BString& _M_get_storage(__bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir>  const& __ref) {

    _M_Init(__ref);

    return _M_storage;

  }

  size_t size() const { return 0; }

  _CharT const& operator[](size_t __n) const

  { return __STATIC_CAST(_CharT*, 0)[__n]; }

private:

  mutable bool _M_init;

  mutable basic_string<_CharT, _Traits, _Alloc> _M_storage;

};

_STLP_MOVE_TO_STD_NAMESPACE

_STLP_END_NAMESPACE

#endif /*_STLP_STRING_SUM_H*/