libcxx/test/std/numerics/bit/bit.pow.two/bit_ceil.verify.cpp

   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: c++03, c++11, c++14, c++17
  10
  11 // template <class T>
  12 //   constexpr T bit_ceil(T x) noexcept;
  13
  14 // Remarks: This function shall not participate in overload resolution unless
  15 //          T is an unsigned integer type
  16
  17 #include <bit>
  18 #include <cassert>
  19 #include <cstddef>
  20 #include <cstdint>
  21 #include <limits>
  22
  23 class A{};
  24 enum       E1 : unsigned char { rEd };
  25 enum class E2 : unsigned char { red };
  26
  27 template <typename T>
  28 constexpr bool toobig()
  29 {
  30     return 0 == std::bit_ceil(std::numeric_limits<T>::max());
  31 }
  32
  33 int main(int, char**)
  34 {
  35     // Make sure we generate a compile-time error for UB
  36     static_assert(toobig<unsigned char>(),      ""); // expected-error {{static assertion expression is not an integral constant expression}}
  37     static_assert(toobig<unsigned short>(),     ""); // expected-error {{static assertion expression is not an integral constant expression}}
  38     static_assert(toobig<unsigned>(),           ""); // expected-error {{static assertion expression is not an integral constant expression}}
  39     static_assert(toobig<unsigned long>(),      ""); // expected-error {{static assertion expression is not an integral constant expression}}
  40     static_assert(toobig<unsigned long long>(), ""); // expected-error {{static assertion expression is not an integral constant expression}}
  41
  42     static_assert(toobig<std::uint8_t>(), "");   // expected-error {{static assertion expression is not an integral constant expression}}
  43     static_assert(toobig<std::uint16_t>(), "");  // expected-error {{static assertion expression is not an integral constant expression}}
  44     static_assert(toobig<std::uint32_t>(), "");  // expected-error {{static assertion expression is not an integral constant expression}}
  45     static_assert(toobig<std::uint64_t>(), "");  // expected-error {{static assertion expression is not an integral constant expression}}
  46     static_assert(toobig<std::size_t>(), "");    // expected-error {{static assertion expression is not an integral constant expression}}
  47     static_assert(toobig<std::uintmax_t>(), ""); // expected-error {{static assertion expression is not an integral constant expression}}
  48     static_assert(toobig<std::uintptr_t>(), ""); // expected-error {{static assertion expression is not an integral constant expression}}
  49
  50     return 0;
  51 }