fpos.h (fpos::operator-): Don't return reference, return original, non-modified version.

2001-06-12  Benjamin Kosnik  <bkoz@redhat.com>

	* include/bits/fpos.h (fpos::operator-): Don't return reference,
	return original, non-modified version.
	(fpos::operator+): Same.
	* testsuite/27_io/fpos.cc: Add test.

[[Split portion of a mixed commit.]]

From-SVN: r43290.2

libstdc++-v3/ChangeLog

@@ -3,7 +3,8 @@
 	* include/bits/fpos.h (fpos::operator-): Don't return reference,
 	return original, non-modified version.
 	(fpos::operator+): Same.
-
+	* testsuite/27_io/fpos.cc: Add test.
+	
 2001-06-12  Loren J. Rittle  <ljrittle@acm.org>
 
 	libstdc++/2071

libstdc++-v3/testsuite/27_io/fpos.cc

@@ -107,12 +107,18 @@ void test02()
   pos03 = pos03 + off02;
   pos04 += off02;
   VERIFY( pos03 == pos04 );
+  std::streampos pos05 = pos03;
+  std::streampos pos06 = pos03 + off02;
+  VERIFY ( pos05 == pos03 );
 
   // q = p - o
   // p -= o
   pos03 = pos03 - off02;
   pos04 -= off02;
   VERIFY( pos03 == pos04 );
+  std::streampos pos07 = pos03;
+  std::streampos pos08 = pos03 - off02;
+  VERIFY ( pos07 == pos03 );
 
   // o = p - q
   VERIFY( 0 == pos03 - pos04 );