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 <algorithm> 20 #include <stdexcept> 21 #include <cassert> 22 23 #include "test_macros.h" 24 25 template<typename CharT> 26 void test1(std::basic_string_view<CharT> sv, size_t n, size_t pos) { 27 std::basic_string_view<CharT> sv1; 28 #ifdef TEST_HAS_NO_EXCEPTIONS 29 if (pos > sv.size()) 30 return ; // would throw if exceptions were enabled 31 sv1 = sv.substr(pos, n); 32 #else 33 try { 34 sv1 = sv.substr(pos, n); 35 assert(pos <= sv.size()); 36 } 37 catch (const std::out_of_range&) { 38 assert(pos > sv.size()); 39 return ; 40 } 41 #endif 42 const size_t rlen = std::min(n, sv.size() - pos); 43 assert (sv1.size() == rlen); 44 for (size_t i = 0; i < rlen; ++i) 45 assert(sv[pos+i] == sv1[i]); 46 } 47 48 49 template<typename CharT> 50 void test ( const CharT *s ) { 51 typedef std::basic_string_view<CharT> string_view_t; 52 53 string_view_t sv1 ( s ); 54 55 test1(sv1, 0, 0); 56 test1(sv1, 1, 0); 57 test1(sv1, 20, 0); 58 test1(sv1, sv1.size(), 0); 59 60 test1(sv1, 0, 3); 61 test1(sv1, 2, 3); 62 test1(sv1, 100, 3); 63 64 test1(sv1, 0, string_view_t::npos); 65 test1(sv1, 2, string_view_t::npos); 66 test1(sv1, sv1.size(), string_view_t::npos); 67 68 test1(sv1, sv1.size() + 1, 0); 69 test1(sv1, sv1.size() + 1, 1); 70 test1(sv1, sv1.size() + 1, string_view_t::npos); 71 } 72 73 int main () { 74 test ( "ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" ); 75 test ( "ABCDE"); 76 test ( "a" ); 77 test ( "" ); 78 79 test ( L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" ); 80 test ( L"ABCDE" ); 81 test ( L"a" ); 82 test ( L"" ); 83 84 #if TEST_STD_VER >= 11 85 test ( u"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" ); 86 test ( u"ABCDE" ); 87 test ( u"a" ); 88 test ( u"" ); 89 90 test ( U"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE" ); 91 test ( U"ABCDE" ); 92 test ( U"a" ); 93 test ( U"" ); 94 #endif 95 96 #if TEST_STD_VER > 11 97 { 98 constexpr std::string_view sv1 { "ABCDE", 5 }; 99 100 { 101 constexpr std::string_view sv2 = sv1.substr ( 0, 3 ); 102 static_assert ( sv2.size() == 3, "" ); 103 static_assert ( sv2[0] == 'A', "" ); 104 static_assert ( sv2[1] == 'B', "" ); 105 static_assert ( sv2[2] == 'C', "" ); 106 } 107 108 { 109 constexpr std::string_view sv2 = sv1.substr ( 3, 0 ); 110 static_assert ( sv2.size() == 0, "" ); 111 } 112 113 { 114 constexpr std::string_view sv2 = sv1.substr ( 3, 3 ); 115 static_assert ( sv2.size() == 2, "" ); 116 static_assert ( sv2[0] == 'D', "" ); 117 static_assert ( sv2[1] == 'E', "" ); 118 } 119 } 120 #endif 121 } 122
