basic_string.tcc (_S_construct(_InIterator, _InIterator, const _Alloc&, input_iterato...

2004-01-30  Paolo Carlini  <pcarlini@suse.de>

	* include/bits/basic_string.tcc (_S_construct(_InIterator,
	_InIterator, const _Alloc&, input_iterator_tag)): Simplify
	the double loop, streamline.

	* include/bits/basic_string.tcc: Very minor tweaks.

From-SVN: r76937

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 2baf985..e13c44a 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2004-01-30  Paolo Carlini  <pcarlini@suse.de>
+
+       * include/bits/basic_string.tcc (_S_construct(_InIterator,
+       _InIterator, const _Alloc&, input_iterator_tag)): Simplify
+       the double loop, streamline.
+
+       * include/bits/basic_string.tcc: Very minor tweaks.
+
 2004-01-30  Loren J. Rittle  <ljrittle@acm.org>
 
        * scripts/check_performance: Only compile with $THREAD_FLAG

diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
index 80ee245..a478a4c 100644 (file)
--- a/libstdc++-v3/include/bits/basic_string.tcc
+++ b/libstdc++-v3/include/bits/basic_string.tcc
@@ -92,45 +92,29 @@ namespace std
          return _S_empty_rep()._M_refdata();
        // Avoid reallocation for common case.
        _CharT __buf[100];
-       size_type __i = 0;
-       while (__beg != __end && __i < sizeof(__buf) / sizeof(_CharT))
+       size_type __len = 0;
+       while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
          { 
-           __buf[__i++] = *__beg; 
-           ++__beg; 
+           __buf[__len++] = *__beg; 
+           ++__beg;
          }
-       _Rep* __r = _Rep::_S_create(__i, size_type(0), __a);
-       traits_type::copy(__r->_M_refdata(), __buf, __i);
-       __r->_M_length = __i;
+       _Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
+       traits_type::copy(__r->_M_refdata(), __buf, __len);
        try 
          {
-           // NB: this loop looks precisely this way because
-           // it avoids comparing __beg != __end any more
-           // than strictly necessary; != might be expensive!
-           for (;;)
+           while (__beg != __end)
              {
-               _CharT* __p = __r->_M_refdata() + __r->_M_length;
-               _CharT* __last = __r->_M_refdata() + __r->_M_capacity;
-               for (;;)
+               if (__len == __r->_M_capacity)
                  {
-                   if (__beg == __end)
-                     {
-                       __r->_M_length = __p - __r->_M_refdata();
-                       *__p = _Rep::_S_terminal;       // grrr.
-                       return __r->_M_refdata();
-                     }
-                   if (__p == __last)
-                     break;
-                   *__p++ = *__beg; 
-                   ++__beg;
+                   // Allocate more space.
+                   _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
+                   traits_type::copy(__another->_M_refdata(), 
+                                     __r->_M_refdata(), __len);
+                   __r->_M_destroy(__a);
+                   __r = __another;
                  }
-               // Allocate more space.
-               const size_type __len = __r->_M_capacity;
-               _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
-               traits_type::copy(__another->_M_refdata(), 
-                                 __r->_M_refdata(), __len);
-               __r->_M_destroy(__a);
-               __r = __another;
-               __r->_M_length = __len;
+               __r->_M_refdata()[__len++] = *__beg; 
+               ++__beg;
              }
          }
        catch(...) 
@@ -138,7 +122,9 @@ namespace std
            __r->_M_destroy(__a); 
            __throw_exception_again;
          }
-       return 0;
+       __r->_M_length = __len;
+       __r->_M_refdata()[__len] = _Rep::_S_terminal;       // grrr.
+       return __r->_M_refdata();
       }
   
   template<typename _CharT, typename _Traits, typename _Alloc>
@@ -167,7 +153,6 @@ namespace std
            __throw_exception_again;
          }
        __r->_M_length = __dnew;
-
        __r->_M_refdata()[__dnew] = _Rep::_S_terminal;  // grrr.
        return __r->_M_refdata();
       }
@@ -209,9 +194,8 @@ namespace std
     : _M_dataplus(_S_construct(__str._M_data()
                               + __str._M_check(__pos,
                                                "basic_string::basic_string"),
-                              __str._M_data() + __pos 
-                              + __str._M_limit(__pos, __n),
-                              _Alloc()), _Alloc())
+                              __str._M_data() + __str._M_limit(__pos, __n)
+                              + __pos, _Alloc()), _Alloc())
     { }
 
   template<typename _CharT, typename _Traits, typename _Alloc>
@@ -221,8 +205,8 @@ namespace std
     : _M_dataplus(_S_construct(__str._M_data()
                               + __str._M_check(__pos,
                                                "basic_string::basic_string"),
-                              __str._M_data() + __pos
-                              + __str._M_limit(__pos, __n), __a), __a)
+                              __str._M_data() + __str._M_limit(__pos, __n)
+                              + __pos, __a), __a)
     { }
 
   // TBD: DPG annotate
@@ -262,7 +246,7 @@ namespace std
       if (_M_rep() != __str._M_rep())
        {
          // XXX MT
-         allocator_type __a = this->get_allocator();
+         const allocator_type __a = this->get_allocator();
          _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
          _M_rep()->_M_dispose(__a);
          _M_data(__tmp);