[patch] bits/string.tcc and testsuite/21_strings/rfind.cc

[brent verner <brent at rcfile dot org>]

Attached is a (finally correct) patch to bits/string.tcc that brings
the implementation in conformance with the std (IMNSVO). Also, 
testsuite/21_strings/rfind.cc to verify the new behavior. Please
disregard any earlier comments/patches/crap I sent about this issue...
my brain just came fully back online :)


[with this patch, the following prog...]
#include <string>
#include <iostream>
using namespace std;
int
main()
{
  string a("learning");
  string c;
  for(unsigned i = 0;i<=a.size()+1;++i)
    cout << a.rfind(c,i) << endl;
}

[will output]
0
1
2
3
4
5
6
7
8
8

-- 
Damon Brent Verner
Cracker JackŪ Certified Professional
brent@rcfile.org, brent@linux1.org
Index: bits/string.tcc
===================================================================
RCS file: /cvs/gcc/egcs/libstdc++-v3/bits/string.tcc,v
retrieving revision 1.5
diff -c -p -r1.5 string.tcc
*** string.tcc	2000/06/20 23:14:37	1.5
--- string.tcc	2000/06/24 04:07:19
*************** namespace std
*** 634,647 ****
        size_type __size = this->size();
        if (__n <= __size)
  	{
! 	  size_t __xpos = __size - __n;
! 	  if (__xpos > __pos)
! 	    __xpos = __pos;
!       
! 	  for (++__xpos; __xpos-- > 0; )
! 	    if (traits_type::eq(_M_data()[__xpos], *__s)
! 		&& traits_type::compare(_M_data() + __xpos, __s, __n) == 0)
! 	      return __xpos;
  	}
        return npos;
      }
--- 634,645 ----
        size_type __size = this->size();
        if (__n <= __size)
  	{
! 	  __pos = std::min(__size - __n ,__pos);
! 	  const _CharT* __data = _M_data();
! 	  do {
! 	    if (traits_type::compare(__data + __pos, __s, __n) == 0)
! 	      return __pos;
! 	  } while (__pos-- > 0);
  	}
        return npos;
      }
// 2000-06-22 -=dbv=-  (shamelessy copied from bkoz' find.cc)

// Copyright (C) 1994, 1999, 2000 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.


#include <string>
#include <stdexcept>
#ifdef DEBUG_ASSERT
#include <assert.h>
#endif

// 21.3.6.2 basic_string rfind
bool test01(void)
{
  bool test = true;
  typedef std::string::size_type csize_type;
  typedef std::string::const_reference cref;
  typedef std::string::reference ref;
  csize_type npos = std::string::npos;
  csize_type csz01, csz02;

  const char str_lit01[] = "mave";
  const std::string str01("mavericks, santa cruz");
  std::string str02(str_lit01);
  std::string str03("s, s");
  std::string str04;
  
  // size_type rfind(const string&, size_type pos = 0) const;
  csz01 = str01.rfind(str01);
  test &= csz01 == 0;
  csz01 = str01.rfind(str01, 4);
  test &= csz01 == 0;
  csz01 = str01.rfind(str02,3);
  test &= csz01 == 0;
  csz01 = str01.rfind(str02);
  test &= csz01 == 0;
  csz01 = str01.rfind(str03);
  test &= csz01 == 8;
  csz01 = str01.rfind(str03, 3);
  test &= csz01 == npos;
  csz01 = str01.rfind(str03, 12);
  test &= csz01 == 8;
  
  // An empty string consists of no characters
  // therefore it should be found at every point in a string,
  // except beyond the end
  csz01 = str01.rfind(str04, 0);
  test &= csz01 == 0;
  csz01 = str01.rfind(str04, 5);
  test &= csz01 == 5;
  csz01 = str01.rfind(str04, str01.size());
  test &= csz01 == str01.size(); 
  csz01 = str01.rfind(str04, str01.size()+1);
  test &= csz01 == str01.size();
  
  // size_type rfind(const char* s, size_type pos, size_type n) const;
  csz01 = str01.rfind(str_lit01, 0, 3);
  test &= csz01 == 0;
  csz01 = str01.rfind(str_lit01, 3, 0);
  test &= csz01 == 3;
  
  // size_type rfind(const char* s, size_type pos = 0) const;
  csz01 = str01.rfind(str_lit01);
  test &= csz01 == 0;
  csz01 = str01.rfind(str_lit01, 3);
  test &= csz01 == 0;
  
  // size_type rfind(char c, size_type pos = 0) const;
  csz01 = str01.rfind('z');
  csz02 = str01.size() - 1;
  test &= csz01 == csz02;
  csz01 = str01.rfind('/');
  test &= csz01 == npos; 
  
#ifdef DEBUG_ASSERT
  assert(test);
#endif
  return test;
}

// 21.3.6.4 basic_string::find_last_of
bool test02()
{
  bool test = true;

  // test find_last_of

#ifdef DEBUG_ASSERT
  assert(test);
#endif
  return test;
}

// 21.3.6.6 basic_string::find_last_not_of
bool test03()
{
  bool test = true;

  // test find_last_not_of

#ifdef DEBUG_ASSERT
  assert(test);
#endif
  return test;
}
int main()
{ 
  test01();
  test02();
  test03();
}