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 int compare(size_type pos1, size_type n1, const charT* s) const;
13 
14 #include <string_view>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 #include "constexpr_char_traits.hpp"
19 
20 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
21 
22 template<typename CharT>
23 void test1 ( std::basic_string_view<CharT> sv1,
24              size_t pos1, size_t n1, const CharT *s, int expected ) {
25     try {
26         assert(sign(sv1.compare(pos1, n1, s)) == sign(expected));
27         assert(pos1 <= sv1.size());
28     }
29     catch (const std::out_of_range&) {
30         assert(pos1 > sv1.size());
31     }
32 }
33 
34 template<typename CharT>
35 void
36 test( const CharT *s1, size_t pos1, size_t n1, const CharT *s2, int expected)
37 {
38     typedef std::basic_string_view<CharT> string_view_t;
39     string_view_t sv1 ( s1 );
40     test1 ( sv1, pos1, n1, s2, expected );
41 }
42 
43 void test0()
44 {
45     test("", 0, 0, "", 0);
46     test("", 0, 0, "abcde", -5);
47     test("", 0, 0, "abcdefghij", -10);
48     test("", 0, 0, "abcdefghijklmnopqrst", -20);
49     test("", 0, 1, "", 0);
50     test("", 0, 1, "abcde", -5);
51     test("", 0, 1, "abcdefghij", -10);
52     test("", 0, 1, "abcdefghijklmnopqrst", -20);
53     test("", 1, 0, "", 0);
54     test("", 1, 0, "abcde", 0);
55     test("", 1, 0, "abcdefghij", 0);
56     test("", 1, 0, "abcdefghijklmnopqrst", 0);
57     test("abcde", 0, 0, "", 0);
58     test("abcde", 0, 0, "abcde", -5);
59     test("abcde", 0, 0, "abcdefghij", -10);
60     test("abcde", 0, 0, "abcdefghijklmnopqrst", -20);
61     test("abcde", 0, 1, "", 1);
62     test("abcde", 0, 1, "abcde", -4);
63     test("abcde", 0, 1, "abcdefghij", -9);
64     test("abcde", 0, 1, "abcdefghijklmnopqrst", -19);
65     test("abcde", 0, 2, "", 2);
66     test("abcde", 0, 2, "abcde", -3);
67     test("abcde", 0, 2, "abcdefghij", -8);
68     test("abcde", 0, 2, "abcdefghijklmnopqrst", -18);
69     test("abcde", 0, 4, "", 4);
70     test("abcde", 0, 4, "abcde", -1);
71     test("abcde", 0, 4, "abcdefghij", -6);
72     test("abcde", 0, 4, "abcdefghijklmnopqrst", -16);
73     test("abcde", 0, 5, "", 5);
74     test("abcde", 0, 5, "abcde", 0);
75     test("abcde", 0, 5, "abcdefghij", -5);
76     test("abcde", 0, 5, "abcdefghijklmnopqrst", -15);
77     test("abcde", 0, 6, "", 5);
78     test("abcde", 0, 6, "abcde", 0);
79     test("abcde", 0, 6, "abcdefghij", -5);
80     test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
81     test("abcde", 1, 0, "", 0);
82     test("abcde", 1, 0, "abcde", -5);
83     test("abcde", 1, 0, "abcdefghij", -10);
84     test("abcde", 1, 0, "abcdefghijklmnopqrst", -20);
85     test("abcde", 1, 1, "", 1);
86     test("abcde", 1, 1, "abcde", 1);
87     test("abcde", 1, 1, "abcdefghij", 1);
88     test("abcde", 1, 1, "abcdefghijklmnopqrst", 1);
89     test("abcde", 1, 2, "", 2);
90     test("abcde", 1, 2, "abcde", 1);
91     test("abcde", 1, 2, "abcdefghij", 1);
92     test("abcde", 1, 2, "abcdefghijklmnopqrst", 1);
93     test("abcde", 1, 3, "", 3);
94     test("abcde", 1, 3, "abcde", 1);
95     test("abcde", 1, 3, "abcdefghij", 1);
96     test("abcde", 1, 3, "abcdefghijklmnopqrst", 1);
97     test("abcde", 1, 4, "", 4);
98     test("abcde", 1, 4, "abcde", 1);
99     test("abcde", 1, 4, "abcdefghij", 1);
100     test("abcde", 1, 4, "abcdefghijklmnopqrst", 1);
101     test("abcde", 1, 5, "", 4);
102     test("abcde", 1, 5, "abcde", 1);
103     test("abcde", 1, 5, "abcdefghij", 1);
104     test("abcde", 1, 5, "abcdefghijklmnopqrst", 1);
105     test("abcde", 2, 0, "", 0);
106     test("abcde", 2, 0, "abcde", -5);
107     test("abcde", 2, 0, "abcdefghij", -10);
108     test("abcde", 2, 0, "abcdefghijklmnopqrst", -20);
109     test("abcde", 2, 1, "", 1);
110     test("abcde", 2, 1, "abcde", 2);
111     test("abcde", 2, 1, "abcdefghij", 2);
112     test("abcde", 2, 1, "abcdefghijklmnopqrst", 2);
113     test("abcde", 2, 2, "", 2);
114     test("abcde", 2, 2, "abcde", 2);
115     test("abcde", 2, 2, "abcdefghij", 2);
116     test("abcde", 2, 2, "abcdefghijklmnopqrst", 2);
117     test("abcde", 2, 3, "", 3);
118     test("abcde", 2, 3, "abcde", 2);
119     test("abcde", 2, 3, "abcdefghij", 2);
120     test("abcde", 2, 3, "abcdefghijklmnopqrst", 2);
121     test("abcde", 2, 4, "", 3);
122     test("abcde", 2, 4, "abcde", 2);
123     test("abcde", 2, 4, "abcdefghij", 2);
124     test("abcde", 2, 4, "abcdefghijklmnopqrst", 2);
125     test("abcde", 4, 0, "", 0);
126     test("abcde", 4, 0, "abcde", -5);
127     test("abcde", 4, 0, "abcdefghij", -10);
128     test("abcde", 4, 0, "abcdefghijklmnopqrst", -20);
129     test("abcde", 4, 1, "", 1);
130     test("abcde", 4, 1, "abcde", 4);
131     test("abcde", 4, 1, "abcdefghij", 4);
132     test("abcde", 4, 1, "abcdefghijklmnopqrst", 4);
133     test("abcde", 4, 2, "", 1);
134     test("abcde", 4, 2, "abcde", 4);
135     test("abcde", 4, 2, "abcdefghij", 4);
136     test("abcde", 4, 2, "abcdefghijklmnopqrst", 4);
137     test("abcde", 5, 0, "", 0);
138     test("abcde", 5, 0, "abcde", -5);
139     test("abcde", 5, 0, "abcdefghij", -10);
140     test("abcde", 5, 0, "abcdefghijklmnopqrst", -20);
141     test("abcde", 5, 1, "", 0);
142     test("abcde", 5, 1, "abcde", -5);
143     test("abcde", 5, 1, "abcdefghij", -10);
144     test("abcde", 5, 1, "abcdefghijklmnopqrst", -20);
145 }
146 
147 void test1()
148 {
149     test("abcde", 6, 0, "", 0);
150     test("abcde", 6, 0, "abcde", 0);
151     test("abcde", 6, 0, "abcdefghij", 0);
152     test("abcde", 6, 0, "abcdefghijklmnopqrst", 0);
153     test("abcdefghij", 0, 0, "", 0);
154     test("abcdefghij", 0, 0, "abcde", -5);
155     test("abcdefghij", 0, 0, "abcdefghij", -10);
156     test("abcdefghij", 0, 0, "abcdefghijklmnopqrst", -20);
157     test("abcdefghij", 0, 1, "", 1);
158     test("abcdefghij", 0, 1, "abcde", -4);
159     test("abcdefghij", 0, 1, "abcdefghij", -9);
160     test("abcdefghij", 0, 1, "abcdefghijklmnopqrst", -19);
161     test("abcdefghij", 0, 5, "", 5);
162     test("abcdefghij", 0, 5, "abcde", 0);
163     test("abcdefghij", 0, 5, "abcdefghij", -5);
164     test("abcdefghij", 0, 5, "abcdefghijklmnopqrst", -15);
165     test("abcdefghij", 0, 9, "", 9);
166     test("abcdefghij", 0, 9, "abcde", 4);
167     test("abcdefghij", 0, 9, "abcdefghij", -1);
168     test("abcdefghij", 0, 9, "abcdefghijklmnopqrst", -11);
169     test("abcdefghij", 0, 10, "", 10);
170     test("abcdefghij", 0, 10, "abcde", 5);
171     test("abcdefghij", 0, 10, "abcdefghij", 0);
172     test("abcdefghij", 0, 10, "abcdefghijklmnopqrst", -10);
173     test("abcdefghij", 0, 11, "", 10);
174     test("abcdefghij", 0, 11, "abcde", 5);
175     test("abcdefghij", 0, 11, "abcdefghij", 0);
176     test("abcdefghij", 0, 11, "abcdefghijklmnopqrst", -10);
177     test("abcdefghij", 1, 0, "", 0);
178     test("abcdefghij", 1, 0, "abcde", -5);
179     test("abcdefghij", 1, 0, "abcdefghij", -10);
180     test("abcdefghij", 1, 0, "abcdefghijklmnopqrst", -20);
181     test("abcdefghij", 1, 1, "", 1);
182     test("abcdefghij", 1, 1, "abcde", 1);
183     test("abcdefghij", 1, 1, "abcdefghij", 1);
184     test("abcdefghij", 1, 1, "abcdefghijklmnopqrst", 1);
185     test("abcdefghij", 1, 4, "", 4);
186     test("abcdefghij", 1, 4, "abcde", 1);
187     test("abcdefghij", 1, 4, "abcdefghij", 1);
188     test("abcdefghij", 1, 4, "abcdefghijklmnopqrst", 1);
189     test("abcdefghij", 1, 8, "", 8);
190     test("abcdefghij", 1, 8, "abcde", 1);
191     test("abcdefghij", 1, 8, "abcdefghij", 1);
192     test("abcdefghij", 1, 8, "abcdefghijklmnopqrst", 1);
193     test("abcdefghij", 1, 9, "", 9);
194     test("abcdefghij", 1, 9, "abcde", 1);
195     test("abcdefghij", 1, 9, "abcdefghij", 1);
196     test("abcdefghij", 1, 9, "abcdefghijklmnopqrst", 1);
197     test("abcdefghij", 1, 10, "", 9);
198     test("abcdefghij", 1, 10, "abcde", 1);
199     test("abcdefghij", 1, 10, "abcdefghij", 1);
200     test("abcdefghij", 1, 10, "abcdefghijklmnopqrst", 1);
201     test("abcdefghij", 5, 0, "", 0);
202     test("abcdefghij", 5, 0, "abcde", -5);
203     test("abcdefghij", 5, 0, "abcdefghij", -10);
204     test("abcdefghij", 5, 0, "abcdefghijklmnopqrst", -20);
205     test("abcdefghij", 5, 1, "", 1);
206     test("abcdefghij", 5, 1, "abcde", 5);
207     test("abcdefghij", 5, 1, "abcdefghij", 5);
208     test("abcdefghij", 5, 1, "abcdefghijklmnopqrst", 5);
209     test("abcdefghij", 5, 2, "", 2);
210     test("abcdefghij", 5, 2, "abcde", 5);
211     test("abcdefghij", 5, 2, "abcdefghij", 5);
212     test("abcdefghij", 5, 2, "abcdefghijklmnopqrst", 5);
213     test("abcdefghij", 5, 4, "", 4);
214     test("abcdefghij", 5, 4, "abcde", 5);
215     test("abcdefghij", 5, 4, "abcdefghij", 5);
216     test("abcdefghij", 5, 4, "abcdefghijklmnopqrst", 5);
217     test("abcdefghij", 5, 5, "", 5);
218     test("abcdefghij", 5, 5, "abcde", 5);
219     test("abcdefghij", 5, 5, "abcdefghij", 5);
220     test("abcdefghij", 5, 5, "abcdefghijklmnopqrst", 5);
221     test("abcdefghij", 5, 6, "", 5);
222     test("abcdefghij", 5, 6, "abcde", 5);
223     test("abcdefghij", 5, 6, "abcdefghij", 5);
224     test("abcdefghij", 5, 6, "abcdefghijklmnopqrst", 5);
225     test("abcdefghij", 9, 0, "", 0);
226     test("abcdefghij", 9, 0, "abcde", -5);
227     test("abcdefghij", 9, 0, "abcdefghij", -10);
228     test("abcdefghij", 9, 0, "abcdefghijklmnopqrst", -20);
229     test("abcdefghij", 9, 1, "", 1);
230     test("abcdefghij", 9, 1, "abcde", 9);
231     test("abcdefghij", 9, 1, "abcdefghij", 9);
232     test("abcdefghij", 9, 1, "abcdefghijklmnopqrst", 9);
233     test("abcdefghij", 9, 2, "", 1);
234     test("abcdefghij", 9, 2, "abcde", 9);
235     test("abcdefghij", 9, 2, "abcdefghij", 9);
236     test("abcdefghij", 9, 2, "abcdefghijklmnopqrst", 9);
237     test("abcdefghij", 10, 0, "", 0);
238     test("abcdefghij", 10, 0, "abcde", -5);
239     test("abcdefghij", 10, 0, "abcdefghij", -10);
240     test("abcdefghij", 10, 0, "abcdefghijklmnopqrst", -20);
241     test("abcdefghij", 10, 1, "", 0);
242     test("abcdefghij", 10, 1, "abcde", -5);
243     test("abcdefghij", 10, 1, "abcdefghij", -10);
244     test("abcdefghij", 10, 1, "abcdefghijklmnopqrst", -20);
245     test("abcdefghij", 11, 0, "", 0);
246     test("abcdefghij", 11, 0, "abcde", 0);
247     test("abcdefghij", 11, 0, "abcdefghij", 0);
248     test("abcdefghij", 11, 0, "abcdefghijklmnopqrst", 0);
249 }
250 
251 void test2()
252 {
253     test("abcdefghijklmnopqrst", 0, 0, "", 0);
254     test("abcdefghijklmnopqrst", 0, 0, "abcde", -5);
255     test("abcdefghijklmnopqrst", 0, 0, "abcdefghij", -10);
256     test("abcdefghijklmnopqrst", 0, 0, "abcdefghijklmnopqrst", -20);
257     test("abcdefghijklmnopqrst", 0, 1, "", 1);
258     test("abcdefghijklmnopqrst", 0, 1, "abcde", -4);
259     test("abcdefghijklmnopqrst", 0, 1, "abcdefghij", -9);
260     test("abcdefghijklmnopqrst", 0, 1, "abcdefghijklmnopqrst", -19);
261     test("abcdefghijklmnopqrst", 0, 10, "", 10);
262     test("abcdefghijklmnopqrst", 0, 10, "abcde", 5);
263     test("abcdefghijklmnopqrst", 0, 10, "abcdefghij", 0);
264     test("abcdefghijklmnopqrst", 0, 10, "abcdefghijklmnopqrst", -10);
265     test("abcdefghijklmnopqrst", 0, 19, "", 19);
266     test("abcdefghijklmnopqrst", 0, 19, "abcde", 14);
267     test("abcdefghijklmnopqrst", 0, 19, "abcdefghij", 9);
268     test("abcdefghijklmnopqrst", 0, 19, "abcdefghijklmnopqrst", -1);
269     test("abcdefghijklmnopqrst", 0, 20, "", 20);
270     test("abcdefghijklmnopqrst", 0, 20, "abcde", 15);
271     test("abcdefghijklmnopqrst", 0, 20, "abcdefghij", 10);
272     test("abcdefghijklmnopqrst", 0, 20, "abcdefghijklmnopqrst", 0);
273     test("abcdefghijklmnopqrst", 0, 21, "", 20);
274     test("abcdefghijklmnopqrst", 0, 21, "abcde", 15);
275     test("abcdefghijklmnopqrst", 0, 21, "abcdefghij", 10);
276     test("abcdefghijklmnopqrst", 0, 21, "abcdefghijklmnopqrst", 0);
277     test("abcdefghijklmnopqrst", 1, 0, "", 0);
278     test("abcdefghijklmnopqrst", 1, 0, "abcde", -5);
279     test("abcdefghijklmnopqrst", 1, 0, "abcdefghij", -10);
280     test("abcdefghijklmnopqrst", 1, 0, "abcdefghijklmnopqrst", -20);
281     test("abcdefghijklmnopqrst", 1, 1, "", 1);
282     test("abcdefghijklmnopqrst", 1, 1, "abcde", 1);
283     test("abcdefghijklmnopqrst", 1, 1, "abcdefghij", 1);
284     test("abcdefghijklmnopqrst", 1, 1, "abcdefghijklmnopqrst", 1);
285     test("abcdefghijklmnopqrst", 1, 9, "", 9);
286     test("abcdefghijklmnopqrst", 1, 9, "abcde", 1);
287     test("abcdefghijklmnopqrst", 1, 9, "abcdefghij", 1);
288     test("abcdefghijklmnopqrst", 1, 9, "abcdefghijklmnopqrst", 1);
289     test("abcdefghijklmnopqrst", 1, 18, "", 18);
290     test("abcdefghijklmnopqrst", 1, 18, "abcde", 1);
291     test("abcdefghijklmnopqrst", 1, 18, "abcdefghij", 1);
292     test("abcdefghijklmnopqrst", 1, 18, "abcdefghijklmnopqrst", 1);
293     test("abcdefghijklmnopqrst", 1, 19, "", 19);
294     test("abcdefghijklmnopqrst", 1, 19, "abcde", 1);
295     test("abcdefghijklmnopqrst", 1, 19, "abcdefghij", 1);
296     test("abcdefghijklmnopqrst", 1, 19, "abcdefghijklmnopqrst", 1);
297     test("abcdefghijklmnopqrst", 1, 20, "", 19);
298     test("abcdefghijklmnopqrst", 1, 20, "abcde", 1);
299     test("abcdefghijklmnopqrst", 1, 20, "abcdefghij", 1);
300     test("abcdefghijklmnopqrst", 1, 20, "abcdefghijklmnopqrst", 1);
301     test("abcdefghijklmnopqrst", 10, 0, "", 0);
302     test("abcdefghijklmnopqrst", 10, 0, "abcde", -5);
303     test("abcdefghijklmnopqrst", 10, 0, "abcdefghij", -10);
304     test("abcdefghijklmnopqrst", 10, 0, "abcdefghijklmnopqrst", -20);
305     test("abcdefghijklmnopqrst", 10, 1, "", 1);
306     test("abcdefghijklmnopqrst", 10, 1, "abcde", 10);
307     test("abcdefghijklmnopqrst", 10, 1, "abcdefghij", 10);
308     test("abcdefghijklmnopqrst", 10, 1, "abcdefghijklmnopqrst", 10);
309     test("abcdefghijklmnopqrst", 10, 5, "", 5);
310     test("abcdefghijklmnopqrst", 10, 5, "abcde", 10);
311     test("abcdefghijklmnopqrst", 10, 5, "abcdefghij", 10);
312     test("abcdefghijklmnopqrst", 10, 5, "abcdefghijklmnopqrst", 10);
313     test("abcdefghijklmnopqrst", 10, 9, "", 9);
314     test("abcdefghijklmnopqrst", 10, 9, "abcde", 10);
315     test("abcdefghijklmnopqrst", 10, 9, "abcdefghij", 10);
316     test("abcdefghijklmnopqrst", 10, 9, "abcdefghijklmnopqrst", 10);
317     test("abcdefghijklmnopqrst", 10, 10, "", 10);
318     test("abcdefghijklmnopqrst", 10, 10, "abcde", 10);
319     test("abcdefghijklmnopqrst", 10, 10, "abcdefghij", 10);
320     test("abcdefghijklmnopqrst", 10, 10, "abcdefghijklmnopqrst", 10);
321     test("abcdefghijklmnopqrst", 10, 11, "", 10);
322     test("abcdefghijklmnopqrst", 10, 11, "abcde", 10);
323     test("abcdefghijklmnopqrst", 10, 11, "abcdefghij", 10);
324     test("abcdefghijklmnopqrst", 10, 11, "abcdefghijklmnopqrst", 10);
325     test("abcdefghijklmnopqrst", 19, 0, "", 0);
326     test("abcdefghijklmnopqrst", 19, 0, "abcde", -5);
327     test("abcdefghijklmnopqrst", 19, 0, "abcdefghij", -10);
328     test("abcdefghijklmnopqrst", 19, 0, "abcdefghijklmnopqrst", -20);
329     test("abcdefghijklmnopqrst", 19, 1, "", 1);
330     test("abcdefghijklmnopqrst", 19, 1, "abcde", 19);
331     test("abcdefghijklmnopqrst", 19, 1, "abcdefghij", 19);
332     test("abcdefghijklmnopqrst", 19, 1, "abcdefghijklmnopqrst", 19);
333     test("abcdefghijklmnopqrst", 19, 2, "", 1);
334     test("abcdefghijklmnopqrst", 19, 2, "abcde", 19);
335     test("abcdefghijklmnopqrst", 19, 2, "abcdefghij", 19);
336     test("abcdefghijklmnopqrst", 19, 2, "abcdefghijklmnopqrst", 19);
337     test("abcdefghijklmnopqrst", 20, 0, "", 0);
338     test("abcdefghijklmnopqrst", 20, 0, "abcde", -5);
339     test("abcdefghijklmnopqrst", 20, 0, "abcdefghij", -10);
340     test("abcdefghijklmnopqrst", 20, 0, "abcdefghijklmnopqrst", -20);
341     test("abcdefghijklmnopqrst", 20, 1, "", 0);
342     test("abcdefghijklmnopqrst", 20, 1, "abcde", -5);
343     test("abcdefghijklmnopqrst", 20, 1, "abcdefghij", -10);
344     test("abcdefghijklmnopqrst", 20, 1, "abcdefghijklmnopqrst", -20);
345     test("abcdefghijklmnopqrst", 21, 0, "", 0);
346     test("abcdefghijklmnopqrst", 21, 0, "abcde", 0);
347     test("abcdefghijklmnopqrst", 21, 0, "abcdefghij", 0);
348     test("abcdefghijklmnopqrst", 21, 0, "abcdefghijklmnopqrst", 0);
349 }
350 
351 
352 int main()
353 {
354     test0();
355     test1();
356     test2();
357 
358     {
359     test("", 0, 0, "", 0);
360     test("", 0, 0, "abcde", -5);
361     test("", 0, 0, "abcdefghij", -10);
362     test("", 0, 0, "abcdefghijklmnopqrst", -20);
363     test("abcde", 0, 2, "", 5);
364     test("abcde", 0, 6,"abcde", 0);
365     test("abcde", 0, 6, "abcdefghij", -5);
366     test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
367     test("abcdefghij", 3, 3, "", 10);
368     test("abcdefghij", 3, 3,"abcde", 5);
369     test("abcdefghij", 3, 3, "def", 0);
370     test("abcdefghij", 0, 4, "abcdefghijklmnopqrst", -10);
371     test("abcdefghijklmnopqrst", 5, 5, "", 20);
372     test("abcdefghijklmnopqrst", 0, 8, "abcde", 15);
373     test("abcdefghijklmnopqrst", 0, 12, "abcdefghij", 10);
374     test("abcdefghijklmnopqrst", 0, -1, "abcdefghijklmnopqrst", 0);
375     }
376 
377     {
378     test(L"", 0, 0, L"", 0);
379     test(L"", 0, 0, L"abcde", -5);
380     test(L"", 0, 0, L"abcdefghij", -10);
381     test(L"", 0, 0, L"abcdefghijklmnopqrst", -20);
382     test(L"abcde", 0, 2, L"", 5);
383     test(L"abcde", 0, 6, L"abcde", 0);
384     test(L"abcde", 0, 6, L"abcdefghij", -5);
385     test(L"abcde", 0, 6, L"abcdefghijklmnopqrst", -15);
386     test(L"abcdefghij", 3, 3, L"", 10);
387     test(L"abcdefghij", 3, 3, L"abcde", 5);
388     test(L"abcdefghij", 3, 3, L"def", 0);
389     test(L"abcdefghij", 0, 4, L"abcdefghijklmnopqrst", -10);
390     test(L"abcdefghijklmnopqrst", 5, 5, L"", 20);
391     test(L"abcdefghijklmnopqrst", 0, 8, L"abcde", 15);
392     test(L"abcdefghijklmnopqrst", 0, 12, L"abcdefghij", 10);
393     test(L"abcdefghijklmnopqrst", 0, -1, L"abcdefghijklmnopqrst", 0);
394     }
395 
396 #if TEST_STD_VER >= 11
397     {
398     test(U"", 0, 0, U"", 0);
399     test(U"", 0, 0, U"abcde", -5);
400     test(U"", 0, 0, U"abcdefghij", -10);
401     test(U"", 0, 0, U"abcdefghijklmnopqrst", -20);
402     test(U"abcde", 0, 2, U"", 5);
403     test(U"abcde", 0, 6, U"abcde", 0);
404     test(U"abcde", 0, 6, U"abcdefghij", -5);
405     test(U"abcde", 0, 6, U"abcdefghijklmnopqrst", -15);
406     test(U"abcdefghij", 3, 3, U"", 10);
407     test(U"abcdefghij", 3, 3, U"abcde", 5);
408     test(U"abcdefghij", 3, 3, U"def", 0);
409     test(U"abcdefghij", 0, 4, U"abcdefghijklmnopqrst", -10);
410     test(U"abcdefghijklmnopqrst", 5, 5, U"", 20);
411     test(U"abcdefghijklmnopqrst", 0, 8, U"abcde", 15);
412     test(U"abcdefghijklmnopqrst", 0, 12, U"abcdefghij", 10);
413     test(U"abcdefghijklmnopqrst", 0, -1, U"abcdefghijklmnopqrst", 0);
414     }
415 
416     {
417     test(u"", 0, 0, u"", 0);
418     test(u"", 0, 0, u"abcde", -5);
419     test(u"", 0, 0, u"abcdefghij", -10);
420     test(u"", 0, 0, u"abcdefghijklmnopqrst", -20);
421     test(u"abcde", 0, 2, u"", 5);
422     test(u"abcde", 0, 6, u"abcde", 0);
423     test(u"abcde", 0, 6, u"abcdefghij", -5);
424     test(u"abcde", 0, 6, u"abcdefghijklmnopqrst", -15);
425     test(u"abcdefghij", 3, 3, u"", 10);
426     test(u"abcdefghij", 3, 3, u"abcde", 5);
427     test(u"abcdefghij", 3, 3, u"def", 0);
428     test(u"abcdefghij", 0, 4, u"abcdefghijklmnopqrst", -10);
429     test(u"abcdefghijklmnopqrst", 5, 5, u"", 20);
430     test(u"abcdefghijklmnopqrst", 0, 8, u"abcde", 15);
431     test(u"abcdefghijklmnopqrst", 0, 12, u"abcdefghij", 10);
432     test(u"abcdefghijklmnopqrst", 0, -1, u"abcdefghijklmnopqrst", 0);
433     }
434 #endif
435 
436 #if TEST_STD_VER > 11
437     {
438     typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
439     constexpr SV  sv1;
440     constexpr SV  sv2 { "abcde", 5 };
441     static_assert ( sv1.compare(0, 0, "") == 0, "" );
442     static_assert ( sv1.compare(0, 0, "abcde") == -1, "" );
443     static_assert ( sv2.compare(0, 2, "") == 1, "" );
444     static_assert ( sv2.compare(0, 6, "abcde") == 0, "" );
445     }
446 #endif
447 }
448