1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14) 10 11 // <string_view> 12 13 // void remove_prefix(size_type _n) 14 15 #include <string_view> 16 #include <cassert> 17 18 #include "test_macros.h" 19 20 template<typename CharT> 21 void test ( const CharT *s, size_t len ) { 22 typedef std::basic_string_view<CharT> SV; 23 { 24 SV sv1 ( s ); 25 assert ( sv1.size() == len ); 26 assert ( sv1.data() == s ); 27 28 if ( len > 0 ) { 29 sv1.remove_prefix ( 1 ); 30 assert ( sv1.size() == (len - 1)); 31 assert ( sv1.data() == (s + 1)); 32 sv1.remove_prefix ( len - 1 ); 33 } 34 35 assert ( sv1.size() == 0 ); 36 sv1.remove_prefix ( 0 ); 37 assert ( sv1.size() == 0 ); 38 } 39 } 40 41 #if TEST_STD_VER > 11 42 constexpr size_t test_ce ( size_t n, size_t k ) { 43 typedef std::basic_string_view<char> SV; 44 SV sv1{ "ABCDEFGHIJKL", n }; 45 sv1.remove_prefix ( k ); 46 return sv1.size(); 47 } 48 #endif 49 50 int main(int, char**) { 51 test ( "ABCDE", 5 ); 52 test ( "a", 1 ); 53 test ( "", 0 ); 54 55 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 56 test ( L"ABCDE", 5 ); 57 test ( L"a", 1 ); 58 test ( L"", 0 ); 59 #endif 60 61 #if TEST_STD_VER >= 11 62 test ( u"ABCDE", 5 ); 63 test ( u"a", 1 ); 64 test ( u"", 0 ); 65 66 test ( U"ABCDE", 5 ); 67 test ( U"a", 1 ); 68 test ( U"", 0 ); 69 #endif 70 71 #if TEST_STD_VER > 11 72 { 73 static_assert ( test_ce ( 5, 0 ) == 5, "" ); 74 static_assert ( test_ce ( 5, 1 ) == 4, "" ); 75 static_assert ( test_ce ( 5, 5 ) == 0, "" ); 76 static_assert ( test_ce ( 9, 3 ) == 6, "" ); 77 } 78 #endif 79 80 return 0; 81 } 82