change to fix failures with gcc 4.1+

modification to string input primitives

[SVN r41770]

libs/serialization

@@ -1 +1 @@
-Subproject commit 23b6906d8c4bf20e10b99819cb98fb71fe36a402
+Subproject commit 1681869ffaba29842a8e7f1852e7e1cf63c03550