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      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 #include <stdexcept>
     17 
     18 #include "test_macros.h"
     19 #include "constexpr_char_traits.hpp"
     20 
     21 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
     22 
     23 template<typename CharT>
     24 void test1 ( std::basic_string_view<CharT> sv1,
     25              size_t pos1, size_t n1, const CharT *s, int expected ) {
     26 #ifdef TEST_HAS_NO_EXCEPTIONS
     27     if (pos1 <= sv1.size())
     28         assert(sign(sv1.compare(pos1, n1, s)) == sign(expected));
     29 #else
     30     try {
     31         assert(sign(sv1.compare(pos1, n1, s)) == sign(expected));
     32         assert(pos1 <= sv1.size());
     33     }
     34     catch (const std::out_of_range&) {
     35         assert(pos1 > sv1.size());
     36     }
     37 #endif
     38 }
     39 
     40 template<typename CharT>
     41 void
     42 test( const CharT *s1, size_t pos1, size_t n1, const CharT *s2, int expected)
     43 {
     44     typedef std::basic_string_view<CharT> string_view_t;
     45     string_view_t sv1 ( s1 );
     46     test1 ( sv1, pos1, n1, s2, expected );
     47 }
     48 
     49 void test0()
     50 {
     51     test("", 0, 0, "", 0);
     52     test("", 0, 0, "abcde", -5);
     53     test("", 0, 0, "abcdefghij", -10);
     54     test("", 0, 0, "abcdefghijklmnopqrst", -20);
     55     test("", 0, 1, "", 0);
     56     test("", 0, 1, "abcde", -5);
     57     test("", 0, 1, "abcdefghij", -10);
     58     test("", 0, 1, "abcdefghijklmnopqrst", -20);
     59     test("", 1, 0, "", 0);
     60     test("", 1, 0, "abcde", 0);
     61     test("", 1, 0, "abcdefghij", 0);
     62     test("", 1, 0, "abcdefghijklmnopqrst", 0);
     63     test("abcde", 0, 0, "", 0);
     64     test("abcde", 0, 0, "abcde", -5);
     65     test("abcde", 0, 0, "abcdefghij", -10);
     66     test("abcde", 0, 0, "abcdefghijklmnopqrst", -20);
     67     test("abcde", 0, 1, "", 1);
     68     test("abcde", 0, 1, "abcde", -4);
     69     test("abcde", 0, 1, "abcdefghij", -9);
     70     test("abcde", 0, 1, "abcdefghijklmnopqrst", -19);
     71     test("abcde", 0, 2, "", 2);
     72     test("abcde", 0, 2, "abcde", -3);
     73     test("abcde", 0, 2, "abcdefghij", -8);
     74     test("abcde", 0, 2, "abcdefghijklmnopqrst", -18);
     75     test("abcde", 0, 4, "", 4);
     76     test("abcde", 0, 4, "abcde", -1);
     77     test("abcde", 0, 4, "abcdefghij", -6);
     78     test("abcde", 0, 4, "abcdefghijklmnopqrst", -16);
     79     test("abcde", 0, 5, "", 5);
     80     test("abcde", 0, 5, "abcde", 0);
     81     test("abcde", 0, 5, "abcdefghij", -5);
     82     test("abcde", 0, 5, "abcdefghijklmnopqrst", -15);
     83     test("abcde", 0, 6, "", 5);
     84     test("abcde", 0, 6, "abcde", 0);
     85     test("abcde", 0, 6, "abcdefghij", -5);
     86     test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
     87     test("abcde", 1, 0, "", 0);
     88     test("abcde", 1, 0, "abcde", -5);
     89     test("abcde", 1, 0, "abcdefghij", -10);
     90     test("abcde", 1, 0, "abcdefghijklmnopqrst", -20);
     91     test("abcde", 1, 1, "", 1);
     92     test("abcde", 1, 1, "abcde", 1);
     93     test("abcde", 1, 1, "abcdefghij", 1);
     94     test("abcde", 1, 1, "abcdefghijklmnopqrst", 1);
     95     test("abcde", 1, 2, "", 2);
     96     test("abcde", 1, 2, "abcde", 1);
     97     test("abcde", 1, 2, "abcdefghij", 1);
     98     test("abcde", 1, 2, "abcdefghijklmnopqrst", 1);
     99     test("abcde", 1, 3, "", 3);
    100     test("abcde", 1, 3, "abcde", 1);
    101     test("abcde", 1, 3, "abcdefghij", 1);
    102     test("abcde", 1, 3, "abcdefghijklmnopqrst", 1);
    103     test("abcde", 1, 4, "", 4);
    104     test("abcde", 1, 4, "abcde", 1);
    105     test("abcde", 1, 4, "abcdefghij", 1);
    106     test("abcde", 1, 4, "abcdefghijklmnopqrst", 1);
    107     test("abcde", 1, 5, "", 4);
    108     test("abcde", 1, 5, "abcde", 1);
    109     test("abcde", 1, 5, "abcdefghij", 1);
    110     test("abcde", 1, 5, "abcdefghijklmnopqrst", 1);
    111     test("abcde", 2, 0, "", 0);
    112     test("abcde", 2, 0, "abcde", -5);
    113     test("abcde", 2, 0, "abcdefghij", -10);
    114     test("abcde", 2, 0, "abcdefghijklmnopqrst", -20);
    115     test("abcde", 2, 1, "", 1);
    116     test("abcde", 2, 1, "abcde", 2);
    117     test("abcde", 2, 1, "abcdefghij", 2);
    118     test("abcde", 2, 1, "abcdefghijklmnopqrst", 2);
    119     test("abcde", 2, 2, "", 2);
    120     test("abcde", 2, 2, "abcde", 2);
    121     test("abcde", 2, 2, "abcdefghij", 2);
    122     test("abcde", 2, 2, "abcdefghijklmnopqrst", 2);
    123     test("abcde", 2, 3, "", 3);
    124     test("abcde", 2, 3, "abcde", 2);
    125     test("abcde", 2, 3, "abcdefghij", 2);
    126     test("abcde", 2, 3, "abcdefghijklmnopqrst", 2);
    127     test("abcde", 2, 4, "", 3);
    128     test("abcde", 2, 4, "abcde", 2);
    129     test("abcde", 2, 4, "abcdefghij", 2);
    130     test("abcde", 2, 4, "abcdefghijklmnopqrst", 2);
    131     test("abcde", 4, 0, "", 0);
    132     test("abcde", 4, 0, "abcde", -5);
    133     test("abcde", 4, 0, "abcdefghij", -10);
    134     test("abcde", 4, 0, "abcdefghijklmnopqrst", -20);
    135     test("abcde", 4, 1, "", 1);
    136     test("abcde", 4, 1, "abcde", 4);
    137     test("abcde", 4, 1, "abcdefghij", 4);
    138     test("abcde", 4, 1, "abcdefghijklmnopqrst", 4);
    139     test("abcde", 4, 2, "", 1);
    140     test("abcde", 4, 2, "abcde", 4);
    141     test("abcde", 4, 2, "abcdefghij", 4);
    142     test("abcde", 4, 2, "abcdefghijklmnopqrst", 4);
    143     test("abcde", 5, 0, "", 0);
    144     test("abcde", 5, 0, "abcde", -5);
    145     test("abcde", 5, 0, "abcdefghij", -10);
    146     test("abcde", 5, 0, "abcdefghijklmnopqrst", -20);
    147     test("abcde", 5, 1, "", 0);
    148     test("abcde", 5, 1, "abcde", -5);
    149     test("abcde", 5, 1, "abcdefghij", -10);
    150     test("abcde", 5, 1, "abcdefghijklmnopqrst", -20);
    151 }
    152 
    153 void test1()
    154 {
    155     test("abcde", 6, 0, "", 0);
    156     test("abcde", 6, 0, "abcde", 0);
    157     test("abcde", 6, 0, "abcdefghij", 0);
    158     test("abcde", 6, 0, "abcdefghijklmnopqrst", 0);
    159     test("abcdefghij", 0, 0, "", 0);
    160     test("abcdefghij", 0, 0, "abcde", -5);
    161     test("abcdefghij", 0, 0, "abcdefghij", -10);
    162     test("abcdefghij", 0, 0, "abcdefghijklmnopqrst", -20);
    163     test("abcdefghij", 0, 1, "", 1);
    164     test("abcdefghij", 0, 1, "abcde", -4);
    165     test("abcdefghij", 0, 1, "abcdefghij", -9);
    166     test("abcdefghij", 0, 1, "abcdefghijklmnopqrst", -19);
    167     test("abcdefghij", 0, 5, "", 5);
    168     test("abcdefghij", 0, 5, "abcde", 0);
    169     test("abcdefghij", 0, 5, "abcdefghij", -5);
    170     test("abcdefghij", 0, 5, "abcdefghijklmnopqrst", -15);
    171     test("abcdefghij", 0, 9, "", 9);
    172     test("abcdefghij", 0, 9, "abcde", 4);
    173     test("abcdefghij", 0, 9, "abcdefghij", -1);
    174     test("abcdefghij", 0, 9, "abcdefghijklmnopqrst", -11);
    175     test("abcdefghij", 0, 10, "", 10);
    176     test("abcdefghij", 0, 10, "abcde", 5);
    177     test("abcdefghij", 0, 10, "abcdefghij", 0);
    178     test("abcdefghij", 0, 10, "abcdefghijklmnopqrst", -10);
    179     test("abcdefghij", 0, 11, "", 10);
    180     test("abcdefghij", 0, 11, "abcde", 5);
    181     test("abcdefghij", 0, 11, "abcdefghij", 0);
    182     test("abcdefghij", 0, 11, "abcdefghijklmnopqrst", -10);
    183     test("abcdefghij", 1, 0, "", 0);
    184     test("abcdefghij", 1, 0, "abcde", -5);
    185     test("abcdefghij", 1, 0, "abcdefghij", -10);
    186     test("abcdefghij", 1, 0, "abcdefghijklmnopqrst", -20);
    187     test("abcdefghij", 1, 1, "", 1);
    188     test("abcdefghij", 1, 1, "abcde", 1);
    189     test("abcdefghij", 1, 1, "abcdefghij", 1);
    190     test("abcdefghij", 1, 1, "abcdefghijklmnopqrst", 1);
    191     test("abcdefghij", 1, 4, "", 4);
    192     test("abcdefghij", 1, 4, "abcde", 1);
    193     test("abcdefghij", 1, 4, "abcdefghij", 1);
    194     test("abcdefghij", 1, 4, "abcdefghijklmnopqrst", 1);
    195     test("abcdefghij", 1, 8, "", 8);
    196     test("abcdefghij", 1, 8, "abcde", 1);
    197     test("abcdefghij", 1, 8, "abcdefghij", 1);
    198     test("abcdefghij", 1, 8, "abcdefghijklmnopqrst", 1);
    199     test("abcdefghij", 1, 9, "", 9);
    200     test("abcdefghij", 1, 9, "abcde", 1);
    201     test("abcdefghij", 1, 9, "abcdefghij", 1);
    202     test("abcdefghij", 1, 9, "abcdefghijklmnopqrst", 1);
    203     test("abcdefghij", 1, 10, "", 9);
    204     test("abcdefghij", 1, 10, "abcde", 1);
    205     test("abcdefghij", 1, 10, "abcdefghij", 1);
    206     test("abcdefghij", 1, 10, "abcdefghijklmnopqrst", 1);
    207     test("abcdefghij", 5, 0, "", 0);
    208     test("abcdefghij", 5, 0, "abcde", -5);
    209     test("abcdefghij", 5, 0, "abcdefghij", -10);
    210     test("abcdefghij", 5, 0, "abcdefghijklmnopqrst", -20);
    211     test("abcdefghij", 5, 1, "", 1);
    212     test("abcdefghij", 5, 1, "abcde", 5);
    213     test("abcdefghij", 5, 1, "abcdefghij", 5);
    214     test("abcdefghij", 5, 1, "abcdefghijklmnopqrst", 5);
    215     test("abcdefghij", 5, 2, "", 2);
    216     test("abcdefghij", 5, 2, "abcde", 5);
    217     test("abcdefghij", 5, 2, "abcdefghij", 5);
    218     test("abcdefghij", 5, 2, "abcdefghijklmnopqrst", 5);
    219     test("abcdefghij", 5, 4, "", 4);
    220     test("abcdefghij", 5, 4, "abcde", 5);
    221     test("abcdefghij", 5, 4, "abcdefghij", 5);
    222     test("abcdefghij", 5, 4, "abcdefghijklmnopqrst", 5);
    223     test("abcdefghij", 5, 5, "", 5);
    224     test("abcdefghij", 5, 5, "abcde", 5);
    225     test("abcdefghij", 5, 5, "abcdefghij", 5);
    226     test("abcdefghij", 5, 5, "abcdefghijklmnopqrst", 5);
    227     test("abcdefghij", 5, 6, "", 5);
    228     test("abcdefghij", 5, 6, "abcde", 5);
    229     test("abcdefghij", 5, 6, "abcdefghij", 5);
    230     test("abcdefghij", 5, 6, "abcdefghijklmnopqrst", 5);
    231     test("abcdefghij", 9, 0, "", 0);
    232     test("abcdefghij", 9, 0, "abcde", -5);
    233     test("abcdefghij", 9, 0, "abcdefghij", -10);
    234     test("abcdefghij", 9, 0, "abcdefghijklmnopqrst", -20);
    235     test("abcdefghij", 9, 1, "", 1);
    236     test("abcdefghij", 9, 1, "abcde", 9);
    237     test("abcdefghij", 9, 1, "abcdefghij", 9);
    238     test("abcdefghij", 9, 1, "abcdefghijklmnopqrst", 9);
    239     test("abcdefghij", 9, 2, "", 1);
    240     test("abcdefghij", 9, 2, "abcde", 9);
    241     test("abcdefghij", 9, 2, "abcdefghij", 9);
    242     test("abcdefghij", 9, 2, "abcdefghijklmnopqrst", 9);
    243     test("abcdefghij", 10, 0, "", 0);
    244     test("abcdefghij", 10, 0, "abcde", -5);
    245     test("abcdefghij", 10, 0, "abcdefghij", -10);
    246     test("abcdefghij", 10, 0, "abcdefghijklmnopqrst", -20);
    247     test("abcdefghij", 10, 1, "", 0);
    248     test("abcdefghij", 10, 1, "abcde", -5);
    249     test("abcdefghij", 10, 1, "abcdefghij", -10);
    250     test("abcdefghij", 10, 1, "abcdefghijklmnopqrst", -20);
    251     test("abcdefghij", 11, 0, "", 0);
    252     test("abcdefghij", 11, 0, "abcde", 0);
    253     test("abcdefghij", 11, 0, "abcdefghij", 0);
    254     test("abcdefghij", 11, 0, "abcdefghijklmnopqrst", 0);
    255 }
    256 
    257 void test2()
    258 {
    259     test("abcdefghijklmnopqrst", 0, 0, "", 0);
    260     test("abcdefghijklmnopqrst", 0, 0, "abcde", -5);
    261     test("abcdefghijklmnopqrst", 0, 0, "abcdefghij", -10);
    262     test("abcdefghijklmnopqrst", 0, 0, "abcdefghijklmnopqrst", -20);
    263     test("abcdefghijklmnopqrst", 0, 1, "", 1);
    264     test("abcdefghijklmnopqrst", 0, 1, "abcde", -4);
    265     test("abcdefghijklmnopqrst", 0, 1, "abcdefghij", -9);
    266     test("abcdefghijklmnopqrst", 0, 1, "abcdefghijklmnopqrst", -19);
    267     test("abcdefghijklmnopqrst", 0, 10, "", 10);
    268     test("abcdefghijklmnopqrst", 0, 10, "abcde", 5);
    269     test("abcdefghijklmnopqrst", 0, 10, "abcdefghij", 0);
    270     test("abcdefghijklmnopqrst", 0, 10, "abcdefghijklmnopqrst", -10);
    271     test("abcdefghijklmnopqrst", 0, 19, "", 19);
    272     test("abcdefghijklmnopqrst", 0, 19, "abcde", 14);
    273     test("abcdefghijklmnopqrst", 0, 19, "abcdefghij", 9);
    274     test("abcdefghijklmnopqrst", 0, 19, "abcdefghijklmnopqrst", -1);
    275     test("abcdefghijklmnopqrst", 0, 20, "", 20);
    276     test("abcdefghijklmnopqrst", 0, 20, "abcde", 15);
    277     test("abcdefghijklmnopqrst", 0, 20, "abcdefghij", 10);
    278     test("abcdefghijklmnopqrst", 0, 20, "abcdefghijklmnopqrst", 0);
    279     test("abcdefghijklmnopqrst", 0, 21, "", 20);
    280     test("abcdefghijklmnopqrst", 0, 21, "abcde", 15);
    281     test("abcdefghijklmnopqrst", 0, 21, "abcdefghij", 10);
    282     test("abcdefghijklmnopqrst", 0, 21, "abcdefghijklmnopqrst", 0);
    283     test("abcdefghijklmnopqrst", 1, 0, "", 0);
    284     test("abcdefghijklmnopqrst", 1, 0, "abcde", -5);
    285     test("abcdefghijklmnopqrst", 1, 0, "abcdefghij", -10);
    286     test("abcdefghijklmnopqrst", 1, 0, "abcdefghijklmnopqrst", -20);
    287     test("abcdefghijklmnopqrst", 1, 1, "", 1);
    288     test("abcdefghijklmnopqrst", 1, 1, "abcde", 1);
    289     test("abcdefghijklmnopqrst", 1, 1, "abcdefghij", 1);
    290     test("abcdefghijklmnopqrst", 1, 1, "abcdefghijklmnopqrst", 1);
    291     test("abcdefghijklmnopqrst", 1, 9, "", 9);
    292     test("abcdefghijklmnopqrst", 1, 9, "abcde", 1);
    293     test("abcdefghijklmnopqrst", 1, 9, "abcdefghij", 1);
    294     test("abcdefghijklmnopqrst", 1, 9, "abcdefghijklmnopqrst", 1);
    295     test("abcdefghijklmnopqrst", 1, 18, "", 18);
    296     test("abcdefghijklmnopqrst", 1, 18, "abcde", 1);
    297     test("abcdefghijklmnopqrst", 1, 18, "abcdefghij", 1);
    298     test("abcdefghijklmnopqrst", 1, 18, "abcdefghijklmnopqrst", 1);
    299     test("abcdefghijklmnopqrst", 1, 19, "", 19);
    300     test("abcdefghijklmnopqrst", 1, 19, "abcde", 1);
    301     test("abcdefghijklmnopqrst", 1, 19, "abcdefghij", 1);
    302     test("abcdefghijklmnopqrst", 1, 19, "abcdefghijklmnopqrst", 1);
    303     test("abcdefghijklmnopqrst", 1, 20, "", 19);
    304     test("abcdefghijklmnopqrst", 1, 20, "abcde", 1);
    305     test("abcdefghijklmnopqrst", 1, 20, "abcdefghij", 1);
    306     test("abcdefghijklmnopqrst", 1, 20, "abcdefghijklmnopqrst", 1);
    307     test("abcdefghijklmnopqrst", 10, 0, "", 0);
    308     test("abcdefghijklmnopqrst", 10, 0, "abcde", -5);
    309     test("abcdefghijklmnopqrst", 10, 0, "abcdefghij", -10);
    310     test("abcdefghijklmnopqrst", 10, 0, "abcdefghijklmnopqrst", -20);
    311     test("abcdefghijklmnopqrst", 10, 1, "", 1);
    312     test("abcdefghijklmnopqrst", 10, 1, "abcde", 10);
    313     test("abcdefghijklmnopqrst", 10, 1, "abcdefghij", 10);
    314     test("abcdefghijklmnopqrst", 10, 1, "abcdefghijklmnopqrst", 10);
    315     test("abcdefghijklmnopqrst", 10, 5, "", 5);
    316     test("abcdefghijklmnopqrst", 10, 5, "abcde", 10);
    317     test("abcdefghijklmnopqrst", 10, 5, "abcdefghij", 10);
    318     test("abcdefghijklmnopqrst", 10, 5, "abcdefghijklmnopqrst", 10);
    319     test("abcdefghijklmnopqrst", 10, 9, "", 9);
    320     test("abcdefghijklmnopqrst", 10, 9, "abcde", 10);
    321     test("abcdefghijklmnopqrst", 10, 9, "abcdefghij", 10);
    322     test("abcdefghijklmnopqrst", 10, 9, "abcdefghijklmnopqrst", 10);
    323     test("abcdefghijklmnopqrst", 10, 10, "", 10);
    324     test("abcdefghijklmnopqrst", 10, 10, "abcde", 10);
    325     test("abcdefghijklmnopqrst", 10, 10, "abcdefghij", 10);
    326     test("abcdefghijklmnopqrst", 10, 10, "abcdefghijklmnopqrst", 10);
    327     test("abcdefghijklmnopqrst", 10, 11, "", 10);
    328     test("abcdefghijklmnopqrst", 10, 11, "abcde", 10);
    329     test("abcdefghijklmnopqrst", 10, 11, "abcdefghij", 10);
    330     test("abcdefghijklmnopqrst", 10, 11, "abcdefghijklmnopqrst", 10);
    331     test("abcdefghijklmnopqrst", 19, 0, "", 0);
    332     test("abcdefghijklmnopqrst", 19, 0, "abcde", -5);
    333     test("abcdefghijklmnopqrst", 19, 0, "abcdefghij", -10);
    334     test("abcdefghijklmnopqrst", 19, 0, "abcdefghijklmnopqrst", -20);
    335     test("abcdefghijklmnopqrst", 19, 1, "", 1);
    336     test("abcdefghijklmnopqrst", 19, 1, "abcde", 19);
    337     test("abcdefghijklmnopqrst", 19, 1, "abcdefghij", 19);
    338     test("abcdefghijklmnopqrst", 19, 1, "abcdefghijklmnopqrst", 19);
    339     test("abcdefghijklmnopqrst", 19, 2, "", 1);
    340     test("abcdefghijklmnopqrst", 19, 2, "abcde", 19);
    341     test("abcdefghijklmnopqrst", 19, 2, "abcdefghij", 19);
    342     test("abcdefghijklmnopqrst", 19, 2, "abcdefghijklmnopqrst", 19);
    343     test("abcdefghijklmnopqrst", 20, 0, "", 0);
    344     test("abcdefghijklmnopqrst", 20, 0, "abcde", -5);
    345     test("abcdefghijklmnopqrst", 20, 0, "abcdefghij", -10);
    346     test("abcdefghijklmnopqrst", 20, 0, "abcdefghijklmnopqrst", -20);
    347     test("abcdefghijklmnopqrst", 20, 1, "", 0);
    348     test("abcdefghijklmnopqrst", 20, 1, "abcde", -5);
    349     test("abcdefghijklmnopqrst", 20, 1, "abcdefghij", -10);
    350     test("abcdefghijklmnopqrst", 20, 1, "abcdefghijklmnopqrst", -20);
    351     test("abcdefghijklmnopqrst", 21, 0, "", 0);
    352     test("abcdefghijklmnopqrst", 21, 0, "abcde", 0);
    353     test("abcdefghijklmnopqrst", 21, 0, "abcdefghij", 0);
    354     test("abcdefghijklmnopqrst", 21, 0, "abcdefghijklmnopqrst", 0);
    355 }
    356 
    357 
    358 int main()
    359 {
    360     test0();
    361     test1();
    362     test2();
    363 
    364     {
    365     test("", 0, 0, "", 0);
    366     test("", 0, 0, "abcde", -5);
    367     test("", 0, 0, "abcdefghij", -10);
    368     test("", 0, 0, "abcdefghijklmnopqrst", -20);
    369     test("abcde", 0, 2, "", 5);
    370     test("abcde", 0, 6,"abcde", 0);
    371     test("abcde", 0, 6, "abcdefghij", -5);
    372     test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
    373     test("abcdefghij", 3, 3, "", 10);
    374     test("abcdefghij", 3, 3,"abcde", 5);
    375     test("abcdefghij", 3, 3, "def", 0);
    376     test("abcdefghij", 0, 4, "abcdefghijklmnopqrst", -10);
    377     test("abcdefghijklmnopqrst", 5, 5, "", 20);
    378     test("abcdefghijklmnopqrst", 0, 8, "abcde", 15);
    379     test("abcdefghijklmnopqrst", 0, 12, "abcdefghij", 10);
    380     test("abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), "abcdefghijklmnopqrst", 0);
    381     }
    382 
    383     {
    384     test(L"", 0, 0, L"", 0);
    385     test(L"", 0, 0, L"abcde", -5);
    386     test(L"", 0, 0, L"abcdefghij", -10);
    387     test(L"", 0, 0, L"abcdefghijklmnopqrst", -20);
    388     test(L"abcde", 0, 2, L"", 5);
    389     test(L"abcde", 0, 6, L"abcde", 0);
    390     test(L"abcde", 0, 6, L"abcdefghij", -5);
    391     test(L"abcde", 0, 6, L"abcdefghijklmnopqrst", -15);
    392     test(L"abcdefghij", 3, 3, L"", 10);
    393     test(L"abcdefghij", 3, 3, L"abcde", 5);
    394     test(L"abcdefghij", 3, 3, L"def", 0);
    395     test(L"abcdefghij", 0, 4, L"abcdefghijklmnopqrst", -10);
    396     test(L"abcdefghijklmnopqrst", 5, 5, L"", 20);
    397     test(L"abcdefghijklmnopqrst", 0, 8, L"abcde", 15);
    398     test(L"abcdefghijklmnopqrst", 0, 12, L"abcdefghij", 10);
    399     test(L"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), L"abcdefghijklmnopqrst", 0);
    400     }
    401 
    402 #if TEST_STD_VER >= 11
    403     {
    404     test(U"", 0, 0, U"", 0);
    405     test(U"", 0, 0, U"abcde", -5);
    406     test(U"", 0, 0, U"abcdefghij", -10);
    407     test(U"", 0, 0, U"abcdefghijklmnopqrst", -20);
    408     test(U"abcde", 0, 2, U"", 5);
    409     test(U"abcde", 0, 6, U"abcde", 0);
    410     test(U"abcde", 0, 6, U"abcdefghij", -5);
    411     test(U"abcde", 0, 6, U"abcdefghijklmnopqrst", -15);
    412     test(U"abcdefghij", 3, 3, U"", 10);
    413     test(U"abcdefghij", 3, 3, U"abcde", 5);
    414     test(U"abcdefghij", 3, 3, U"def", 0);
    415     test(U"abcdefghij", 0, 4, U"abcdefghijklmnopqrst", -10);
    416     test(U"abcdefghijklmnopqrst", 5, 5, U"", 20);
    417     test(U"abcdefghijklmnopqrst", 0, 8, U"abcde", 15);
    418     test(U"abcdefghijklmnopqrst", 0, 12, U"abcdefghij", 10);
    419     test(U"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), U"abcdefghijklmnopqrst", 0);
    420     }
    421 
    422     {
    423     test(u"", 0, 0, u"", 0);
    424     test(u"", 0, 0, u"abcde", -5);
    425     test(u"", 0, 0, u"abcdefghij", -10);
    426     test(u"", 0, 0, u"abcdefghijklmnopqrst", -20);
    427     test(u"abcde", 0, 2, u"", 5);
    428     test(u"abcde", 0, 6, u"abcde", 0);
    429     test(u"abcde", 0, 6, u"abcdefghij", -5);
    430     test(u"abcde", 0, 6, u"abcdefghijklmnopqrst", -15);
    431     test(u"abcdefghij", 3, 3, u"", 10);
    432     test(u"abcdefghij", 3, 3, u"abcde", 5);
    433     test(u"abcdefghij", 3, 3, u"def", 0);
    434     test(u"abcdefghij", 0, 4, u"abcdefghijklmnopqrst", -10);
    435     test(u"abcdefghijklmnopqrst", 5, 5, u"", 20);
    436     test(u"abcdefghijklmnopqrst", 0, 8, u"abcde", 15);
    437     test(u"abcdefghijklmnopqrst", 0, 12, u"abcdefghij", 10);
    438     test(u"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1), u"abcdefghijklmnopqrst", 0);
    439     }
    440 #endif
    441 
    442 #if TEST_STD_VER > 11
    443     {
    444     typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
    445     constexpr SV  sv1;
    446     constexpr SV  sv2 { "abcde", 5 };
    447     static_assert ( sv1.compare(0, 0, "") == 0, "" );
    448     static_assert ( sv1.compare(0, 0, "abcde") == -1, "" );
    449     static_assert ( sv2.compare(0, 2, "") == 1, "" );
    450     static_assert ( sv2.compare(0, 6, "abcde") == 0, "" );
    451     }
    452 #endif
    453 }
    454