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 18 namespace LIBC_NAMESPACE { 19 namespace cpp { 20 21 namespace internal { 22 23 template <typename T, T min_value, T max_value> struct integer_impl { 24 static_assert(cpp::is_integral_v<T>); maxinteger_impl25 LIBC_INLINE static constexpr T max() { return max_value; } mininteger_impl26 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 33 template <class T> struct numeric_limits {}; 34 35 // TODO: Add numeric_limits specializations as needed for new types. 36 template <> 37 struct numeric_limits<short> 38 : public internal::integer_impl<short, SHRT_MIN, SHRT_MAX> {}; 39 40 template <> 41 struct numeric_limits<unsigned short> 42 : public internal::integer_impl<unsigned short, 0, USHRT_MAX> {}; 43 44 template <> 45 struct numeric_limits<int> 46 : public internal::integer_impl<int, INT_MIN, INT_MAX> {}; 47 48 template <> 49 struct numeric_limits<unsigned int> 50 : public internal::integer_impl<unsigned int, 0, UINT_MAX> {}; 51 52 template <> 53 struct numeric_limits<long> 54 : public internal::integer_impl<long, LONG_MIN, LONG_MAX> {}; 55 56 template <> 57 struct numeric_limits<unsigned long> 58 : public internal::integer_impl<unsigned long, 0, ULONG_MAX> {}; 59 60 template <> 61 struct numeric_limits<long long> 62 : public internal::integer_impl<long long, LLONG_MIN, LLONG_MAX> {}; 63 64 template <> 65 struct numeric_limits<unsigned long long> 66 : public internal::integer_impl<unsigned long long, 0, ULLONG_MAX> {}; 67 68 template <> 69 struct numeric_limits<char> 70 : public internal::integer_impl<char, CHAR_MIN, CHAR_MAX> {}; 71 72 template <> 73 struct numeric_limits<signed char> 74 : public internal::integer_impl<signed char, SCHAR_MIN, SCHAR_MAX> {}; 75 76 template <> 77 struct 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. 83 template <> 84 struct 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