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 // REQUIRES: long_tests 10 11 // Not a portable test 12 13 // <__hash_table> 14 15 // size_t __next_prime(size_t n); 16 17 // If n == 0, return 0, else return the lowest prime greater than or equal to n 18 19 // XFAIL: FROZEN-CXX03-HEADERS-FIXME 20 21 #include <__hash_table> 22 #include <cassert> 23 #include <cstddef> 24 25 #include "test_macros.h" 26 27 bool 28 is_prime(std::size_t n) 29 { 30 switch (n) 31 { 32 case 0: 33 case 1: 34 return false; 35 } 36 for (std::size_t i = 2; i*i <= n; ++i) 37 { 38 if (n % i == 0) 39 return false; 40 } 41 return true; 42 } 43 44 int main(int, char**) 45 { 46 assert(std::__next_prime(0) == 0); 47 for (std::size_t n = 1; n <= 100000; ++n) 48 { 49 std::size_t p = std::__next_prime(n); 50 assert(p >= n); 51 for (std::size_t i = n; i < p; ++i) 52 assert(!is_prime(i)); 53 assert(is_prime(p)); 54 } 55 56 return 0; 57 } 58