[patch] string::_M_set_lengt_and_sharable clean up

[Paolo Carlini <pcarlini at suse dot de>]

Hi,

this is clean up originally conceived by Benjamin, that I have
further extended to include _M_set_sharable and thus _S_create
too. Probably, will also make easier other rearrangments ...

Tested x86-linux for now, I will further test and commit.

Paolo.

//////////
2004-10-21  Paolo Carlini  <pcarlini@suse.de>
	    Benjamin Kosnik  <bkoz@redhat.com>

	* include/bits/basic_string.h (_M_set_length_and_sharable): New.
	* include/bits/basic_string.tcc (_S_construct, assign(const _CharT*,
	size_type), _M_mutate, _M_clone): Use it.
	(_Rep::_S_create): Don't set/call _M_length/_M_set_sharable here.

diff -urN libstdc++-v3-orig/include/bits/basic_string.h libstdc++-v3/include/bits/basic_string.h
--- libstdc++-v3-orig/include/bits/basic_string.h	2004-10-18 10:43:17.000000000 +0200
+++ libstdc++-v3/include/bits/basic_string.h	2004-10-21 20:17:00.000000000 +0200
@@ -193,6 +193,15 @@
 	_M_set_sharable()
         { this->_M_refcount = 0; }
 
+	void
+	_M_set_length_and_sharable(size_type __n)
+	{ 
+	  this->_M_set_sharable();  // One reference.
+	  this->_M_length = __n;
+	  this->_M_refdata()[__n] = _S_terminal; // grrr. (per 21.3.4)
+	  // You cannot leave those LWG people alone for a second.
+	}
+
 	_CharT*
 	_M_refdata() throw()
 	{ return reinterpret_cast<_CharT*>(this + 1); }
diff -urN libstdc++-v3-orig/include/bits/basic_string.tcc libstdc++-v3/include/bits/basic_string.tcc
--- libstdc++-v3-orig/include/bits/basic_string.tcc	2004-10-18 10:43:17.000000000 +0200
+++ libstdc++-v3/include/bits/basic_string.tcc	2004-10-21 20:18:22.000000000 +0200
@@ -124,8 +124,7 @@
 	    __r->_M_destroy(__a);
 	    __throw_exception_again;
 	  }
-	__r->_M_length = __len;
-	__r->_M_refdata()[__len] = _Rep::_S_terminal;       // grrr.
+	__r->_M_set_length_and_sharable(__len);
 	return __r->_M_refdata();
       }
 
@@ -155,8 +154,7 @@
 	    __r->_M_destroy(__a);
 	    __throw_exception_again;
 	  }
-	__r->_M_length = __dnew;
-	__r->_M_refdata()[__dnew] = _Rep::_S_terminal;  // grrr.
+	__r->_M_set_length_and_sharable(__dnew);
 	return __r->_M_refdata();
       }
 
@@ -174,8 +172,7 @@
       if (__n)
 	traits_type::assign(__r->_M_refdata(), __n, __c);
 
-      __r->_M_length = __n;
-      __r->_M_refdata()[__n] = _Rep::_S_terminal;  // grrr
+      __r->_M_set_length_and_sharable(__n);
       return __r->_M_refdata();
     }
 
@@ -278,9 +275,7 @@
 	     traits_type::copy(_M_data(), __s, __n);
 	   else if (__pos)
 	     traits_type::move(_M_data(), __s, __n);
-	   _M_rep()->_M_set_sharable();
-	   _M_rep()->_M_length = __n;
-	   _M_data()[__n] = _Rep::_S_terminal;  // grr.
+	   _M_rep()->_M_set_length_and_sharable(__n);
 	   return *this;
 	 }
      }
@@ -415,10 +410,7 @@
 	  traits_type::move(_M_data() + __pos + __len2,
 			    _M_data() + __pos + __len1, __how_much);
 	}
-      _M_rep()->_M_set_sharable();
-      _M_rep()->_M_length = __new_size;
-      _M_data()[__new_size] = _Rep::_S_terminal; // grrr. (per 21.3.4)
-      // You cannot leave those LWG people alone for a second.
+      _M_rep()->_M_set_length_and_sharable(__new_size);
     }
 
   template<typename _CharT, typename _Traits, typename _Alloc>
@@ -535,8 +527,6 @@
       void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
       _Rep *__p = new (__place) _Rep;
       __p->_M_capacity = __capacity;
-      __p->_M_set_sharable();  // One reference.
-      __p->_M_length = 0;
       return __p;
     }
 
@@ -550,11 +540,9 @@
       _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
 				  __alloc);
       if (this->_M_length)
-	traits_type::copy(__r->_M_refdata(), _M_refdata(),
-			  this->_M_length);
+	traits_type::copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
 
-      __r->_M_length = this->_M_length;
-      __r->_M_refdata()[this->_M_length] = _Rep::_S_terminal;
+      __r->_M_set_length_and_sharable(this->_M_length);
       return __r->_M_refdata();
     }