libcxx initial import

llvm-svn: 103490
diff --git a/libcxx/test/strings/basic.string/string.nonmembers/string.special/swap.pass.cpp b/libcxx/test/strings/basic.string/string.nonmembers/string.special/swap.pass.cpp
new file mode 100644
index 0000000..91ed562
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.nonmembers/string.special/swap.pass.cpp
@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// ÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class charT, class traits, class Allocator> 
+//   void swap(basic_string<charT,traits,Allocator>& lhs, 
+//             basic_string<charT,traits,Allocator>& rhs);
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+
+template <class S>
+void
+test(S s1, S s2)
+{
+    S s1_ = s1;
+    S s2_ = s2;
+    swap(s1, s2);
+    assert(s1.__invariants());
+    assert(s2.__invariants());
+    assert(s1 == s2_);
+    assert(s2 == s1_);
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), S(""));
+    test(S(""), S("12345"));
+    test(S(""), S("1234567890"));
+    test(S(""), S("12345678901234567890"));
+    test(S("abcde"), S(""));
+    test(S("abcde"), S("12345"));
+    test(S("abcde"), S("1234567890"));
+    test(S("abcde"), S("12345678901234567890"));
+    test(S("abcdefghij"), S(""));
+    test(S("abcdefghij"), S("12345"));
+    test(S("abcdefghij"), S("1234567890"));
+    test(S("abcdefghij"), S("12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), S(""));
+    test(S("abcdefghijklmnopqrst"), S("12345"));
+    test(S("abcdefghijklmnopqrst"), S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), S("12345678901234567890"));
+}