1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // FILE_DEPENDENCIES: underflow.dat, underflow_utf8.dat
10 
11 // <locale>
12 
13 // wbuffer_convert<Codecvt, Elem, Tr>
14 
15 // int_type underflow();
16 
17 // This test is not entirely portable
18 
19 #include <locale>
20 #include <codecvt>
21 #include <fstream>
22 #include <cassert>
23 
24 #include "test_macros.h"
25 
26 struct test_buf
27     : public std::wbuffer_convert<std::codecvt_utf8<wchar_t> >
28 {
29     typedef std::wbuffer_convert<std::codecvt_utf8<wchar_t> > base;
30     typedef base::char_type   char_type;
31     typedef base::int_type    int_type;
32     typedef base::traits_type traits_type;
33 
test_buftest_buf34     explicit test_buf(std::streambuf* sb) : base(sb) {}
35 
ebacktest_buf36     char_type* eback() const {return base::eback();}
gptrtest_buf37     char_type* gptr()  const {return base::gptr();}
egptrtest_buf38     char_type* egptr() const {return base::egptr();}
gbumptest_buf39     void gbump(int n) {base::gbump(n);}
40 
underflowtest_buf41     virtual int_type underflow() {return base::underflow();}
42 };
43 
main(int,char **)44 int main(int, char**)
45 {
46     {
47         std::ifstream bs("underflow.dat");
48         test_buf f(bs.rdbuf());
49         assert(f.eback() == 0);
50         assert(f.gptr() == 0);
51         assert(f.egptr() == 0);
52         assert(f.underflow() == L'1');
53         assert(f.eback() != 0);
54         assert(f.eback() == f.gptr());
55         assert(*f.gptr() == L'1');
56         assert(f.egptr() - f.eback() == 9);
57     }
58     {
59         std::ifstream bs("underflow.dat");
60         test_buf f(bs.rdbuf());
61         assert(f.eback() == 0);
62         assert(f.gptr() == 0);
63         assert(f.egptr() == 0);
64         assert(f.underflow() == L'1');
65         assert(f.eback() != 0);
66         assert(f.eback() == f.gptr());
67         assert(*f.gptr() == L'1');
68         assert(f.egptr() - f.eback() == 9);
69         f.gbump(8);
70         assert(f.sgetc() == L'9');
71         assert(f.eback()[0] == L'1');
72         assert(f.eback()[1] == L'2');
73         assert(f.eback()[2] == L'3');
74         assert(f.eback()[3] == L'4');
75         assert(f.gptr() - f.eback() == 8);
76         assert(*f.gptr() == L'9');
77         assert(f.egptr() - f.gptr() == 1);
78     }
79     {
80         std::ifstream bs("underflow_utf8.dat");
81         test_buf f(bs.rdbuf());
82         assert(f.sbumpc() == 0x4E51);
83         assert(f.sbumpc() == 0x4E52);
84         assert(f.sbumpc() == 0x4E53);
85         assert(f.sbumpc() == test_buf::traits_type::eof());
86     }
87 
88   return 0;
89 }
90