Implement full support for non-pointer pointers in custom allocators for string. This completes the custom pointer support for the entire library.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@185167 91177308-0d34-0410-b5e6-96231b3b80d8

test/strings/basic.string/string.nonmembers/string.io/stream_extract.pass.cpp

@@ -18,6 +18,8 @@
 #include <sstream>
 #include <cassert>
 
+#include "../../min_allocator.h"
+
 int main()
 {
     {
@@ -64,4 +66,52 @@ int main()
         in >> s;
         assert(in.fail());
     }
+#if __cplusplus >= 201103L
+    {
+        typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+        std::istringstream in("a bc defghij");
+        S s("initial text");
+        in >> s;
+        assert(in.good());
+        assert(s == "a");
+        assert(in.peek() == ' ');
+        in >> s;
+        assert(in.good());
+        assert(s == "bc");
+        assert(in.peek() == ' ');
+        in.width(3);
+        in >> s;
+        assert(in.good());
+        assert(s == "def");
+        assert(in.peek() == 'g');
+        in >> s;
+        assert(in.eof());
+        assert(s == "ghij");
+        in >> s;
+        assert(in.fail());
+    }
+    {
+        typedef std::basic_string<wchar_t, std::char_traits<wchar_t>, min_allocator<wchar_t>> S;
+        std::wistringstream in(L"a bc defghij");
+        S s(L"initial text");
+        in >> s;
+        assert(in.good());
+        assert(s == L"a");
+        assert(in.peek() == L' ');
+        in >> s;
+        assert(in.good());
+        assert(s == L"bc");
+        assert(in.peek() == L' ');
+        in.width(3);
+        in >> s;
+        assert(in.good());
+        assert(s == L"def");
+        assert(in.peek() == L'g');
+        in >> s;
+        assert(in.eof());
+        assert(s == L"ghij");
+        in >> s;
+        assert(in.fail());
+    }
+#endif
 }