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 // <string_view>
11 
12 // constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
13 
14 // Throws: out_of_range if pos > size().
15 // Effects: Determines the effective length rlen of the string to reference as the smaller of n and size() - pos.
16 // Returns: basic_string_view(data()+pos, rlen).
17 
18 #include <string_view>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
23 template<typename CharT>
24 void test1(std::basic_string_view<CharT> sv, size_t n, size_t pos) {
25 #ifdef TEST_HAS_NO_EXCEPTIONS
26     if (pos <= sv.size())
27         assert (sign( sv1.compare(pos1, n1, sv2)) == sign(expected));
28 #else
29     try {
30         std::basic_string_view<CharT> sv1 = sv.substr(pos, n);
31         const size_t rlen = std::min(n, sv.size() - pos);
32         assert (sv1.size() == rlen);
33         for (size_t i = 0; i <= rlen; ++i)
34             assert(sv[pos+i] == sv1[i]);
35     }
36     catch (const std::out_of_range&) {
37         assert(pos > sv.size());
38     }
39 #endif
40 }
41 
42 
43 template<typename CharT>
44 void test ( const CharT *s ) {
45     typedef std::basic_string_view<CharT> string_view_t;
46 
47     string_view_t sv1 ( s );
48 
49     test1(sv1,  0, 0);
50     test1(sv1,  1, 0);
51     test1(sv1, 20, 0);
52     test1(sv1, sv1.size(), 0);
53 
54     test1(sv1,   0, 3);
55     test1(sv1,   2, 3);
56     test1(sv1, 100, 3);
57 
58     test1(sv1, 0, string_view_t::npos);
59     test1(sv1, 2, string_view_t::npos);
60     test1(sv1, sv1.size(), string_view_t::npos);
61 
62     test1(sv1, sv1.size() + 1, 0);
63     test1(sv1, sv1.size() + 1, 1);
64     test1(sv1, sv1.size() + 1, string_view_t::npos);
65 }
66 
67 int main () {
68     test ( "ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" );
69     test ( "ABCDE");
70     test ( "a" );
71     test ( "" );
72 
73     test ( L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" );
74     test ( L"ABCDE" );
75     test ( L"a" );
76     test ( L"" );
77 
78 #if TEST_STD_VER >= 11
79     test ( u"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" );
80     test ( u"ABCDE" );
81     test ( u"a" );
82     test ( u"" );
83 
84     test ( U"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" );
85     test ( U"ABCDE" );
86     test ( U"a" );
87     test ( U"" );
88 #endif
89 
90 #if TEST_STD_VER > 11
91     {
92     constexpr std::string_view sv1 { "ABCDE", 5 };
93 
94     {
95     constexpr std::string_view sv2 = sv1.substr ( 0, 3 );
96     static_assert ( sv2.size() == 3, "" );
97     static_assert ( sv2[0] == 'A', "" );
98     static_assert ( sv2[1] == 'B', "" );
99     static_assert ( sv2[2] == 'C', "" );
100     }
101 
102     {
103     constexpr std::string_view sv2 = sv1.substr ( 3, 0 );
104     static_assert ( sv2.size() == 0, "" );
105     }
106 
107     {
108     constexpr std::string_view sv2 = sv1.substr ( 3, 3 );
109     static_assert ( sv2.size() == 2, "" );
110     static_assert ( sv2[0] == 'D', "" );
111     static_assert ( sv2[1] == 'E', "" );
112     }
113     }
114 #endif
115 }
116