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 // <strstream> 11 12 // class strstreambuf 13 14 // int_type underflow(); 15 16 #include <strstream> 17 #include <cassert> 18 19 struct test 20 : public std::strstreambuf 21 { 22 typedef std::strstreambuf base; 23 test(char* gnext_arg, std::streamsize n, char* pbeg_arg = 0) 24 : base(gnext_arg, n, pbeg_arg) {} 25 test(const char* gnext_arg, std::streamsize n) 26 : base(gnext_arg, n) {} 27 28 base::int_type underflow() {return base::underflow();} 29 }; 30 31 int main() 32 { 33 { 34 char buf[10] = "123"; 35 test sb(buf, 0, buf + 3); 36 assert(sb.underflow() == '1'); 37 assert(sb.underflow() == '1'); 38 assert(sb.snextc() == '2'); 39 assert(sb.underflow() == '2'); 40 assert(sb.underflow() == '2'); 41 assert(sb.snextc() == '3'); 42 assert(sb.underflow() == '3'); 43 assert(sb.underflow() == '3'); 44 assert(sb.snextc() == EOF); 45 assert(sb.underflow() == EOF); 46 assert(sb.underflow() == EOF); 47 sb.sputc('4'); 48 assert(sb.underflow() == '4'); 49 assert(sb.underflow() == '4'); 50 } 51 } 52
