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 <cassert> 16 #include <cstddef> 17 #include <string_view> 18 19 #include "test_macros.h" 20 21 template <typename CharT> 22 void test(const CharT* s, std::size_t len) { 23 typedef std::basic_string_view<CharT> SV; 24 { 25 SV sv1(s); 26 assert(sv1.size() == len); 27 assert(sv1.data() == s); 28 29 if (len > 0) { 30 sv1.remove_prefix(1); 31 assert(sv1.size() == (len - 1)); 32 assert(sv1.data() == (s + 1)); 33 sv1.remove_prefix(len - 1); 34 } 35 36 assert(sv1.size() == 0); 37 sv1.remove_prefix(0); 38 assert(sv1.size() == 0); 39 } 40 } 41 42 #if TEST_STD_VER > 11 43 constexpr std::size_t test_ce(size_t n, size_t k) { 44 typedef std::basic_string_view<char> SV; 45 SV sv1{"ABCDEFGHIJKL", n}; 46 sv1.remove_prefix(k); 47 return sv1.size(); 48 } 49 #endif 50 51 int main(int, char**) { 52 test("ABCDE", 5); 53 test("a", 1); 54 test("", 0); 55 56 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 57 test(L"ABCDE", 5); 58 test(L"a", 1); 59 test(L"", 0); 60 #endif 61 62 #if TEST_STD_VER >= 11 63 test(u"ABCDE", 5); 64 test(u"a", 1); 65 test(u"", 0); 66 67 test(U"ABCDE", 5); 68 test(U"a", 1); 69 test(U"", 0); 70 #endif 71 72 #if TEST_STD_VER > 11 73 { 74 static_assert(test_ce(5, 0) == 5, ""); 75 static_assert(test_ce(5, 1) == 4, ""); 76 static_assert(test_ce(5, 5) == 0, ""); 77 static_assert(test_ce(9, 3) == 6, ""); 78 } 79 #endif 80 81 return 0; 82 } 83