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 // int_type sgetc(); 16 17 #include <streambuf> 18 #include <cassert> 19 20 int underflow_called = 0; 21 22 struct test 23 : public std::basic_streambuf<char> 24 { 25 typedef std::basic_streambuf<char> base; 26 testtest27 test() {} 28 setgtest29 void setg(char* gbeg, char* gnext, char* gend) 30 { 31 base::setg(gbeg, gnext, gend); 32 } 33 34 protected: underflowtest35 int_type underflow() 36 { 37 ++underflow_called; 38 return 'a'; 39 } 40 }; 41 main()42int main() 43 { 44 { 45 test t; 46 assert(underflow_called == 0); 47 assert(t.sgetc() == 'a'); 48 assert(underflow_called == 1); 49 char in[] = "ABC"; 50 t.setg(in, in, in+sizeof(in)); 51 assert(t.sgetc() == 'A'); 52 assert(underflow_called == 1); 53 assert(t.sgetc() == 'A'); 54 assert(underflow_called == 1); 55 } 56 } 57