1 files changed, 97 insertions, 0 deletions
diff --git a/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/overflow.pass.cpp b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/overflow.pass.cpp
new file mode 100644
index 00000000000..3abf9423a12
--- /dev/null
+++ b/libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/overflow.pass.cpp
@@ -0,0 +1,97 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <sstream>
+
+// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+// class basic_stringbuf
+
+// int_type overflow(int_type c = traits::eof());
+
+#include <sstream>
+#include <cassert>
+
+int overflow_called = 0;
+
+template <class CharT>
+struct testbuf
+    : public std::basic_stringbuf<CharT>
+{
+    typedef std::basic_stringbuf<CharT> base;
+    explicit testbuf(const std::basic_string<CharT>& str,
+                     std::ios_base::openmode which = std::ios_base::in | std::ios_base::out)
+        : base(str, which) {}
+
+    typename base::int_type
+        overflow(typename base::int_type c = base::type_traits::eof())
+        {++overflow_called; return base::overflow(c);}
+
+    void pbump(int n) {base::pbump(n);}
+};
+
+int main()
+{
+    {
+        testbuf<char> sb("abc");
+        assert(sb.sputc('1') == '1');
+        assert(sb.str() == "1bc");
+        assert(sb.sputc('2') == '2');
+        assert(sb.str() == "12c");
+        assert(sb.sputc('3') == '3');
+        assert(sb.str() == "123");
+        assert(sb.sputc('4') == '4');
+        assert(sb.str() == "1234");
+        assert(sb.sputc('5') == '5');
+        assert(sb.str() == "12345");
+        assert(sb.sputc('6') == '6');
+        assert(sb.str() == "123456");
+        assert(sb.sputc('7') == '7');
+        assert(sb.str() == "1234567");
+        assert(sb.sputc('8') == '8');
+        assert(sb.str() == "12345678");
+        assert(sb.sputc('9') == '9');
+        assert(sb.str() == "123456789");
+        assert(sb.sputc('0') == '0');
+        assert(sb.str() == "1234567890");
+        assert(sb.sputc('1') == '1');
+        assert(sb.str() == "12345678901");
+    }
+    {
+        testbuf<wchar_t> sb(L"abc");
+        assert(sb.sputc(L'1') == L'1');
+        assert(sb.str() == L"1bc");
+        assert(sb.sputc(L'2') == L'2');
+        assert(sb.str() == L"12c");
+        assert(sb.sputc(L'3') == L'3');
+        assert(sb.str() == L"123");
+        assert(sb.sputc(L'4') == L'4');
+        assert(sb.str() == L"1234");
+        assert(sb.sputc(L'5') == L'5');
+        assert(sb.str() == L"12345");
+        assert(sb.sputc(L'6') == L'6');
+        assert(sb.str() == L"123456");
+        assert(sb.sputc(L'7') == L'7');
+        assert(sb.str() == L"1234567");
+        assert(sb.sputc(L'8') == L'8');
+        assert(sb.str() == L"12345678");
+        assert(sb.sputc(L'9') == L'9');
+        assert(sb.str() == L"123456789");
+        assert(sb.sputc(L'0') == L'0');
+        assert(sb.str() == L"1234567890");
+        assert(sb.sputc(L'1') == L'1');
+        assert(sb.str() == L"12345678901");
+    }
+    {
+        testbuf<char> sb("abc", std::ios_base::app | std::ios_base::out);
+        assert(sb.sputc('1') == '1');
+        assert(sb.str() == "abc1");
+        assert(sb.sputc('2') == '2');
+        assert(sb.str() == "abc12");
+    }
+}