base::internal::CheckedSubOp< T, U, typename std::enable_if< std::is_integral< T >::value &&std::is_integral< U >::value >::type > Struct Template Reference

#include <checked_math_impl.h>

Public Types
using	result_type = typename MaxExponentPromotion< T, U >::type

Static Public Member Functions
template<typename V >
static constexpr bool	Do (T x, U y, V *result)

Detailed Description

template<typename T, typename U>
struct base::internal::CheckedSubOp< T, U, typename std::enable_if< std::is_integral< T >::value &&std::is_integral< U >::value >::type >

Definition at line 104 of file checked_math_impl.h.

Member Typedef Documentation

result_type

template<typename T , typename U >

using base::internal::CheckedSubOp< T, U, typename std::enable_if< std::is_integral< T >::value &&std::is_integral< U >::value >::type >::result_type = typename MaxExponentPromotion<T, U>::type

Definition at line 108 of file checked_math_impl.h.

Member Function Documentation

Do()

template<typename T , typename U >

template<typename V >

static constexpr bool base::internal::CheckedSubOp< T, U, typename std::enable_if< std::is_integral< T >::value &&std::is_integral< U >::value >::type >::Do ( T  x, U  y, V *  result  )

inlinestaticconstexpr

Definition at line 110 of file checked_math_impl.h.

                                                {
    // TODO(jschuh) Make this "constexpr if" once we're C++17.
    if (CheckedSubFastOp<T, U>::is_supported)
      return CheckedSubFastOp<T, U>::Do(x, y, result);
 
    // Double the underlying type up to a full machine word.
    using FastPromotion = typename FastIntegerArithmeticPromotion<T, U>::type;
    using Promotion =
        typename std::conditional<(IntegerBitsPlusSign<FastPromotion>::value >
                                   IntegerBitsPlusSign<intptr_t>::value),
                                  typename BigEnoughPromotion<T, U>::type,
                                  FastPromotion>::type;
    // Fail if either operand is out of range for the promoted type.
    // TODO(jschuh): This could be made to work for a broader range of values.
    if (BASE_NUMERICS_UNLIKELY(!IsValueInRangeForNumericType<Promotion>(x) ||
                               !IsValueInRangeForNumericType<Promotion>(y))) {
      return false;
    }
 
    Promotion presult = {};
    bool is_valid = true;
    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
      presult = static_cast<Promotion>(x) - static_cast<Promotion>(y);
    } else {
      is_valid = CheckedSubImpl(static_cast<Promotion>(x),
                                static_cast<Promotion>(y), &presult);
    }
    *result = static_cast<V>(presult);
    return is_valid && IsValueInRangeForNumericType<V>(presult);
  }

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The documentation for this struct was generated from the following file:

• third_party/accessibility/base/numerics/checked_math_impl.h