basic_string.h (insert(__pos, __s, __n)): Optimize by avoiding temporaries and working in-place when possible.

2001-12-28  Paolo Carlini  <pcarlini@unitus.it>
            Nathan Myers  <ncm@cantrip.org>

	* include/bits/basic_string.h (insert(__pos, __s, __n)):
	Optimize by avoiding temporaries and working in-place when possible.
	(insert(__pos1, __str)): Call insert(__pos1, __str, __pos2, __n).
	(insert(__pos1, __str, __pos2, __n)): Call insert(__pos, __s, __n).
	* testsuite/21_strings/insert.cc (test02): New testcases.

Co-Authored-By: Nathan Myers <ncm@cantrip.org>

From-SVN: r48345