decrement.pass.cpp (1622B)
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 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 10 11 // <chrono> 12 // class weekday; 13 14 // constexpr weekday& operator--() noexcept; 15 // constexpr weekday operator--(int) noexcept; 16 17 18 #include <chrono> 19 #include <type_traits> 20 #include <cassert> 21 22 #include "test_macros.h" 23 #include "../../euclidian.h" 24 25 template <typename WD> 26 constexpr bool testConstexpr() 27 { 28 WD wd{1}; 29 if (static_cast<unsigned>(--wd) != 0) return false; 30 if (static_cast<unsigned>(wd--) != 0) return false; 31 if (static_cast<unsigned>(wd) != 6) return false; 32 return true; 33 } 34 35 int main() 36 { 37 using weekday = std::chrono::weekday; 38 ASSERT_NOEXCEPT(--(std::declval<weekday&>()) ); 39 ASSERT_NOEXCEPT( (std::declval<weekday&>())--); 40 41 ASSERT_SAME_TYPE(weekday , decltype( std::declval<weekday&>()--)); 42 ASSERT_SAME_TYPE(weekday&, decltype(--std::declval<weekday&>() )); 43 44 static_assert(testConstexpr<weekday>(), ""); 45 46 for (unsigned i = 0; i <= 6; ++i) 47 { 48 weekday wd(i); 49 assert((static_cast<unsigned>(--wd) == euclidian_subtraction<unsigned, 0, 6>(i, 1))); 50 assert((static_cast<unsigned>(wd--) == euclidian_subtraction<unsigned, 0, 6>(i, 1))); 51 assert((static_cast<unsigned>(wd) == euclidian_subtraction<unsigned, 0, 6>(i, 2))); 52 } 53 }