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 // NOTE: Older versions of clang have a bug where they fail to evalute 11 // string_view::at as a constant expression. 12 // XFAIL: clang-3.4, clang-3.3 13 14 // <string_view> 15 16 // constexpr const _CharT& at(size_type _pos) const; 17 18 #include <experimental/string_view> 19 #include <cassert> 20 21 template <typename CharT> 22 void test ( const CharT *s, size_t len ) { 23 std::experimental::basic_string_view<CharT> sv ( s, len ); 24 assert ( sv.length() == len ); 25 for ( size_t i = 0; i < len; ++i ) { 26 assert ( sv.at(i) == s[i] ); 27 assert ( &sv.at(i) == s + i ); 28 } 29 30 try { sv.at(len); } catch ( const std::out_of_range & ) { return ; } 31 assert ( false ); 32 } 33 34 int main () { 35 test ( "ABCDE", 5 ); 36 test ( "a", 1 ); 37 38 test ( L"ABCDE", 5 ); 39 test ( L"a", 1 ); 40 41 #if __cplusplus >= 201103L 42 test ( u"ABCDE", 5 ); 43 test ( u"a", 1 ); 44 45 test ( U"ABCDE", 5 ); 46 test ( U"a", 1 ); 47 #endif 48 49 #if __cplusplus >= 201103L 50 { 51 constexpr std::experimental::basic_string_view<char> sv ( "ABC", 2 ); 52 static_assert ( sv.length() == 2, "" ); 53 static_assert ( sv.at(0) == 'A', "" ); 54 static_assert ( sv.at(1) == 'B', "" ); 55 } 56 #endif 57 } 58
