libc/src/__support/sign.h

   1 //===-- A simple sign type --------------------------------------*- C++ -*-===//
   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 #ifndef LLVM_LIBC_SRC___SUPPORT_SIGN_H
  10 #define LLVM_LIBC_SRC___SUPPORT_SIGN_H
  11
  12 #include "src/__support/macros/attributes.h" // LIBC_INLINE, LIBC_INLINE_VAR
  13
  14 namespace LIBC_NAMESPACE_DECL {
  15
  16 // A type to interact with signed arithmetic types.
  17 struct Sign {
  18   LIBC_INLINE constexpr bool is_pos() const { return !is_negative; }
  19   LIBC_INLINE constexpr bool is_neg() const { return is_negative; }
  20
  21   LIBC_INLINE friend constexpr bool operator==(Sign a, Sign b) {
  22     return a.is_negative == b.is_negative;
  23   }
  24
  25   LIBC_INLINE friend constexpr bool operator!=(Sign a, Sign b) {
  26     return !(a == b);
  27   }
  28
  29   static const Sign POS;
  30   static const Sign NEG;
  31
  32 private:
  33   LIBC_INLINE constexpr explicit Sign(bool is_negative)
  34       : is_negative(is_negative) {}
  35
  36   bool is_negative;
  37 };
  38
  39 LIBC_INLINE_VAR constexpr Sign Sign::NEG = Sign(true);
  40 LIBC_INLINE_VAR constexpr Sign Sign::POS = Sign(false);
  41
  42 } // namespace LIBC_NAMESPACE_DECL
  43 #endif // LLVM_LIBC_SRC___SUPPORT_SIGN_H