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 // <fstream> 11 12 // int_type underflow(); 13 14 // This test is not entirely portable 15 16 #include <fstream> 17 #include <cassert> 18 19 #include "platform_support.h" // locale name macros 20 21 template <class CharT> 22 struct test_buf 23 : public std::basic_filebuf<CharT> 24 { 25 typedef std::basic_filebuf<CharT> base; 26 typedef typename base::char_type char_type; 27 typedef typename base::int_type int_type; 28 29 char_type* eback() const {return base::eback();} 30 char_type* gptr() const {return base::gptr();} 31 char_type* egptr() const {return base::egptr();} 32 void gbump(int n) {base::gbump(n);} 33 34 virtual int_type underflow() {return base::underflow();} 35 }; 36 37 int main() 38 { 39 { 40 test_buf<char> f; 41 assert(f.open("underflow.dat", std::ios_base::in) != 0); 42 assert(f.is_open()); 43 assert(f.eback() == 0); 44 assert(f.gptr() == 0); 45 assert(f.egptr() == 0); 46 assert(f.underflow() == '1'); 47 assert(f.eback() != 0); 48 assert(f.eback() == f.gptr()); 49 assert(*f.gptr() == '1'); 50 assert(f.egptr() - f.eback() == 9); 51 } 52 { 53 test_buf<char> f; 54 assert(f.open("underflow.dat", std::ios_base::in) != 0); 55 assert(f.pubsetbuf(0, 0)); 56 assert(f.is_open()); 57 assert(f.eback() == 0); 58 assert(f.gptr() == 0); 59 assert(f.egptr() == 0); 60 assert(f.underflow() == '1'); 61 assert(f.eback() != 0); 62 assert(f.eback() == f.gptr()); 63 assert(*f.gptr() == '1'); 64 assert(f.egptr() - f.eback() == 8); 65 f.gbump(8); 66 assert(f.sgetc() == '9'); 67 assert(f.eback()[0] == '5'); 68 assert(f.eback()[1] == '6'); 69 assert(f.eback()[2] == '7'); 70 assert(f.eback()[3] == '8'); 71 assert(f.gptr() - f.eback() == 4); 72 assert(*f.gptr() == '9'); 73 assert(f.egptr() - f.gptr() == 1); 74 } 75 { 76 test_buf<wchar_t> f; 77 assert(f.open("underflow.dat", std::ios_base::in) != 0); 78 assert(f.is_open()); 79 assert(f.eback() == 0); 80 assert(f.gptr() == 0); 81 assert(f.egptr() == 0); 82 assert(f.underflow() == L'1'); 83 assert(f.eback() != 0); 84 assert(f.eback() == f.gptr()); 85 assert(*f.gptr() == L'1'); 86 assert(f.egptr() - f.eback() == 9); 87 } 88 { 89 test_buf<wchar_t> f; 90 assert(f.pubsetbuf(0, 0)); 91 assert(f.open("underflow.dat", std::ios_base::in) != 0); 92 assert(f.is_open()); 93 assert(f.eback() == 0); 94 assert(f.gptr() == 0); 95 assert(f.egptr() == 0); 96 assert(f.underflow() == L'1'); 97 assert(f.eback() != 0); 98 assert(f.eback() == f.gptr()); 99 assert(*f.gptr() == L'1'); 100 assert(f.egptr() - f.eback() == 8); 101 f.gbump(8); 102 assert(f.sgetc() == L'9'); 103 assert(f.eback()[0] == L'5'); 104 assert(f.eback()[1] == L'6'); 105 assert(f.eback()[2] == L'7'); 106 assert(f.eback()[3] == L'8'); 107 assert(f.gptr() - f.eback() == 4); 108 assert(*f.gptr() == L'9'); 109 assert(f.egptr() - f.gptr() == 1); 110 } 111 { 112 test_buf<wchar_t> f; 113 f.pubimbue(std::locale(LOCALE_en_US_UTF_8)); 114 assert(f.open("underflow_utf8.dat", std::ios_base::in) != 0); 115 assert(f.is_open()); 116 assert(f.sbumpc() == 0x4E51); 117 assert(f.sbumpc() == 0x4E52); 118 assert(f.sbumpc() == 0x4E53); 119 assert(f.sbumpc() == -1); 120 } 121 } 122
