libc/src/__support/CPP/limits.h

   1 //===-- A self contained equivalent of std::limits --------------*- 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_CPP_LIMITS_H
  10 #define LLVM_LIBC_SRC_SUPPORT_CPP_LIMITS_H
  11
  12 #include <limits.h>
  13
  14 namespace __llvm_libc {
  15 namespace cpp {
  16
  17 template <class T> class numeric_limits {
  18 public:
  19   static constexpr T max();
  20   static constexpr T min();
  21 };
  22
  23 // TODO: Add numeric_limits specializations as needed for new types.
  24
  25 template <> class numeric_limits<int> {
  26 public:
  27   static constexpr int max() { return INT_MAX; }
  28   static constexpr int min() { return INT_MIN; }
  29 };
  30 template <> class numeric_limits<unsigned int> {
  31 public:
  32   static constexpr unsigned int max() { return UINT_MAX; }
  33   static constexpr unsigned int min() { return 0; }
  34 };
  35 template <> class numeric_limits<long> {
  36 public:
  37   static constexpr long max() { return LONG_MAX; }
  38   static constexpr long min() { return LONG_MIN; }
  39 };
  40 template <> class numeric_limits<unsigned long> {
  41 public:
  42   static constexpr unsigned long max() { return ULONG_MAX; }
  43   static constexpr unsigned long min() { return 0; }
  44 };
  45 template <> class numeric_limits<long long> {
  46 public:
  47   static constexpr long long max() { return LLONG_MAX; }
  48   static constexpr long long min() { return LLONG_MIN; }
  49 };
  50 template <> class numeric_limits<unsigned long long> {
  51 public:
  52   static constexpr unsigned long long max() { return ULLONG_MAX; }
  53   static constexpr unsigned long long min() { return 0; }
  54 };
  55 template <> class numeric_limits<short> {
  56 public:
  57   static constexpr short max() { return SHRT_MAX; }
  58   static constexpr short min() { return SHRT_MIN; }
  59 };
  60 template <> class numeric_limits<unsigned short> {
  61 public:
  62   static constexpr unsigned short max() { return USHRT_MAX; }
  63   static constexpr unsigned short min() { return 0; }
  64 };
  65 template <> class numeric_limits<char> {
  66 public:
  67   static constexpr char max() { return CHAR_MAX; }
  68   static constexpr char min() { return CHAR_MIN; }
  69 };
  70 template <> class numeric_limits<unsigned char> {
  71 public:
  72   static constexpr unsigned char max() { return UCHAR_MAX; }
  73   static constexpr unsigned char min() { return 0; }
  74 };
  75 #ifdef __SIZEOF_INT128__
  76 // On platform where UInt128 resolves to __uint128_t, this specialization
  77 // provides the limits of UInt128.
  78 template <> class numeric_limits<__uint128_t> {
  79 public:
  80   static constexpr __uint128_t max() { return ~__uint128_t(0); }
  81   static constexpr __uint128_t min() { return 0; }
  82 };
  83 #endif
  84
  85 } // namespace cpp
  86 } // namespace __llvm_libc
  87
  88 #endif // LLVM_LIBC_SRC_SUPPORT_CPP_LIMITS_H