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 "include/llvm-libc-macros/limits-macros.h" // CHAR_BIT
13#include "src/__support/CPP/type_traits/is_integral.h"
14#include "src/__support/CPP/type_traits/is_signed.h"
15#include "src/__support/macros/attributes.h" // LIBC_INLINE
16#include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_INT128
17
18namespace LIBC_NAMESPACE {
19namespace cpp {
20
21namespace internal {
22
23template <typename T, T min_value, T max_value> struct integer_impl {
24 static_assert(cpp::is_integral_v<T>);
25 LIBC_INLINE static constexpr T max() { return max_value; }
26 LIBC_INLINE static constexpr T min() { return min_value; }
27 LIBC_INLINE_VAR static constexpr int digits =
28 CHAR_BIT * sizeof(T) - cpp::is_signed_v<T>;
29};
30
31} // namespace internal
32
33template <class T> struct numeric_limits {};
34
35// TODO: Add numeric_limits specializations as needed for new types.
36template <>
37struct numeric_limits<short>
38 : public internal::integer_impl<short, SHRT_MIN, SHRT_MAX> {};
39
40template <>
41struct numeric_limits<unsigned short>
42 : public internal::integer_impl<unsigned short, 0, USHRT_MAX> {};
43
44template <>
45struct numeric_limits<int>
46 : public internal::integer_impl<int, INT_MIN, INT_MAX> {};
47
48template <>
49struct numeric_limits<unsigned int>
50 : public internal::integer_impl<unsigned int, 0, UINT_MAX> {};
51
52template <>
53struct numeric_limits<long>
54 : public internal::integer_impl<long, LONG_MIN, LONG_MAX> {};
55
56template <>
57struct numeric_limits<unsigned long>
58 : public internal::integer_impl<unsigned long, 0, ULONG_MAX> {};
59
60template <>
61struct numeric_limits<long long>
62 : public internal::integer_impl<long long, LLONG_MIN, LLONG_MAX> {};
63
64template <>
65struct numeric_limits<unsigned long long>
66 : public internal::integer_impl<unsigned long long, 0, ULLONG_MAX> {};
67
68template <>
69struct numeric_limits<char>
70 : public internal::integer_impl<char, CHAR_MIN, CHAR_MAX> {};
71
72template <>
73struct numeric_limits<signed char>
74 : public internal::integer_impl<signed char, SCHAR_MIN, SCHAR_MAX> {};
75
76template <>
77struct numeric_limits<unsigned char>
78 : public internal::integer_impl<unsigned char, 0, UCHAR_MAX> {};
79
80#ifdef LIBC_TYPES_HAS_INT128
81// On platform where UInt128 resolves to __uint128_t, this specialization
82// provides the limits of UInt128.
83template <>
84struct numeric_limits<__uint128_t>
85 : public internal::integer_impl<__uint128_t, 0, ~__uint128_t(0)> {};
86#endif
87
88} // namespace cpp
89} // namespace LIBC_NAMESPACE
90
91#endif // LLVM_LIBC_SRC___SUPPORT_CPP_LIMITS_H
92

source code of libc/src/__support/CPP/limits.h