1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <streambuf>
11 
12 // template <class charT, class traits = char_traits<charT> >
13 // class basic_streambuf;
14 
15 // streamsize sgetn(char_type* s, streamsize n);
16 
17 #include <streambuf>
18 #include <cassert>
19 
20 int xsgetn_called = 0;
21 
22 struct test
23     : public std::basic_streambuf<char>
24 {
testtest25     test() {}
26 
27 protected:
xsgetntest28     std::streamsize xsgetn(char_type* s, std::streamsize n)
29     {
30         ++xsgetn_called;
31         return 10;
32     }
33 };
34 
main()35 int main()
36 {
37     test t;
38     assert(xsgetn_called == 0);
39     assert(t.sgetn(0, 0) == 10);
40     assert(xsgetn_called == 1);
41 }
42