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 "hdr/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/config.h" 17 #include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_INT128 18 19 namespace LIBC_NAMESPACE_DECL { 20 namespace cpp { 21 22 namespace internal { 23 24 template <typename T, T min_value, T max_value> struct integer_impl { 25 static_assert(cpp::is_integral_v<T>); maxinteger_impl26 LIBC_INLINE static constexpr T max() { return max_value; } mininteger_impl27 LIBC_INLINE static constexpr T min() { return min_value; } 28 LIBC_INLINE_VAR static constexpr int digits = 29 CHAR_BIT * sizeof(T) - cpp::is_signed_v<T>; 30 }; 31 32 } // namespace internal 33 34 template <class T> struct numeric_limits {}; 35 36 // TODO: Add numeric_limits specializations as needed for new types. 37 template <> 38 struct numeric_limits<short> 39 : public internal::integer_impl<short, SHRT_MIN, SHRT_MAX> {}; 40 41 template <> 42 struct numeric_limits<unsigned short> 43 : public internal::integer_impl<unsigned short, 0, USHRT_MAX> {}; 44 45 template <> 46 struct numeric_limits<int> 47 : public internal::integer_impl<int, INT_MIN, INT_MAX> {}; 48 49 template <> 50 struct numeric_limits<unsigned int> 51 : public internal::integer_impl<unsigned int, 0, UINT_MAX> {}; 52 53 template <> 54 struct numeric_limits<long> 55 : public internal::integer_impl<long, LONG_MIN, LONG_MAX> {}; 56 57 template <> 58 struct numeric_limits<unsigned long> 59 : public internal::integer_impl<unsigned long, 0, ULONG_MAX> {}; 60 61 template <> 62 struct numeric_limits<long long> 63 : public internal::integer_impl<long long, LLONG_MIN, LLONG_MAX> {}; 64 65 template <> 66 struct numeric_limits<unsigned long long> 67 : public internal::integer_impl<unsigned long long, 0, ULLONG_MAX> {}; 68 69 template <> 70 struct numeric_limits<char> 71 : public internal::integer_impl<char, CHAR_MIN, CHAR_MAX> {}; 72 73 template <> 74 struct numeric_limits<signed char> 75 : public internal::integer_impl<signed char, SCHAR_MIN, SCHAR_MAX> {}; 76 77 template <> 78 struct numeric_limits<unsigned char> 79 : public internal::integer_impl<unsigned char, 0, UCHAR_MAX> {}; 80 81 #ifdef LIBC_TYPES_HAS_INT128 82 // On platform where UInt128 resolves to __uint128_t, this specialization 83 // provides the limits of UInt128. 84 template <> 85 struct numeric_limits<__uint128_t> 86 : public internal::integer_impl<__uint128_t, 0, ~__uint128_t(0)> {}; 87 #endif 88 89 } // namespace cpp 90 } // namespace LIBC_NAMESPACE_DECL 91 92 #endif // LLVM_LIBC_SRC___SUPPORT_CPP_LIMITS_H 93