| /* |
| * Copyright (C) 2011 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef CheckedArithmetic_h |
| #define CheckedArithmetic_h |
| |
| #include <wtf/Assertions.h> |
| #include <wtf/TypeTraits.h> |
| |
| #include <limits> |
| #include <stdint.h> |
| |
| /* Checked<T> |
| * |
| * This class provides a mechanism to perform overflow-safe integer arithmetic |
| * without having to manually ensure that you have all the required bounds checks |
| * directly in your code. |
| * |
| * There are two modes of operation: |
| * - The default is Checked<T, CrashOnOverflow>, and crashes at the point |
| * and overflow has occurred. |
| * - The alternative is Checked<T, RecordOverflow>, which uses an additional |
| * byte of storage to track whether an overflow has occurred, subsequent |
| * unchecked operations will crash if an overflow has occured |
| * |
| * It is possible to provide a custom overflow handler, in which case you need |
| * to support these functions: |
| * - void overflowed(); |
| * This function is called when an operation has produced an overflow. |
| * - bool hasOverflowed(); |
| * This function must return true if overflowed() has been called on an |
| * instance and false if it has not. |
| * - void clearOverflow(); |
| * Used to reset overflow tracking when a value is being overwritten with |
| * a new value. |
| * |
| * Checked<T> works for all integer types, with the following caveats: |
| * - Mixing signedness of operands is only supported for types narrower than |
| * 64bits. |
| * - It does have a performance impact, so tight loops may want to be careful |
| * when using it. |
| * |
| */ |
| |
| namespace WTF { |
| |
| class CrashOnOverflow { |
| protected: |
| NO_RETURN_DUE_TO_CRASH void overflowed() |
| { |
| CRASH(); |
| } |
| |
| void clearOverflow() { } |
| |
| public: |
| bool hasOverflowed() const { return false; } |
| }; |
| |
| class RecordOverflow { |
| protected: |
| RecordOverflow() |
| : m_overflowed(false) |
| { |
| } |
| |
| void overflowed() |
| { |
| m_overflowed = true; |
| } |
| |
| void clearOverflow() |
| { |
| m_overflowed = false; |
| } |
| |
| public: |
| bool hasOverflowed() const { return m_overflowed; } |
| |
| private: |
| unsigned char m_overflowed; |
| }; |
| |
| template <typename T, class OverflowHandler = CrashOnOverflow> class Checked; |
| template <typename T> struct RemoveChecked; |
| template <typename T> struct RemoveChecked<Checked<T> >; |
| |
| template <typename Target, typename Source, bool targetSigned = std::numeric_limits<Target>::is_signed, bool sourceSigned = std::numeric_limits<Source>::is_signed> struct BoundsChecker; |
| template <typename Target, typename Source> struct BoundsChecker<Target, Source, false, false> { |
| static bool inBounds(Source value) |
| { |
| // Same signedness so implicit type conversion will always increase precision |
| // to widest type |
| return value <= std::numeric_limits<Target>::max(); |
| } |
| }; |
| |
| template <typename Target, typename Source> struct BoundsChecker<Target, Source, true, true> { |
| static bool inBounds(Source value) |
| { |
| // Same signedness so implicit type conversion will always increase precision |
| // to widest type |
| return std::numeric_limits<Target>::min() <= value && value <= std::numeric_limits<Target>::max(); |
| } |
| }; |
| |
| template <typename Target, typename Source> struct BoundsChecker<Target, Source, false, true> { |
| static bool inBounds(Source value) |
| { |
| // Target is unsigned so any value less than zero is clearly unsafe |
| if (value < 0) |
| return false; |
| // If our (unsigned) Target is the same or greater width we can |
| // convert value to type Target without losing precision |
| if (sizeof(Target) >= sizeof(Source)) |
| return static_cast<Target>(value) <= std::numeric_limits<Target>::max(); |
| // The signed Source type has greater precision than the target so |
| // max(Target) -> Source will widen. |
| return value <= static_cast<Source>(std::numeric_limits<Target>::max()); |
| } |
| }; |
| |
| template <typename Target, typename Source> struct BoundsChecker<Target, Source, true, false> { |
| static bool inBounds(Source value) |
| { |
| // Signed target with an unsigned source |
| if (sizeof(Target) <= sizeof(Source)) |
| return value <= static_cast<Source>(std::numeric_limits<Target>::max()); |
| // Target is Wider than Source so we're guaranteed to fit any value in |
| // unsigned Source |
| return true; |
| } |
| }; |
| |
| template <typename Target, typename Source, bool CanElide = IsSameType<Target, Source>::value || (sizeof(Target) > sizeof(Source)) > struct BoundsCheckElider; |
| template <typename Target, typename Source> struct BoundsCheckElider<Target, Source, true> { |
| static bool inBounds(Source) { return true; } |
| }; |
| template <typename Target, typename Source> struct BoundsCheckElider<Target, Source, false> : public BoundsChecker<Target, Source> { |
| }; |
| |
| template <typename Target, typename Source> static inline bool isInBounds(Source value) |
| { |
| return BoundsCheckElider<Target, Source>::inBounds(value); |
| } |
| |
| template <typename T> struct RemoveChecked { |
| typedef T CleanType; |
| static const CleanType DefaultValue = 0; |
| }; |
| |
| template <typename T> struct RemoveChecked<Checked<T, CrashOnOverflow> > { |
| typedef typename RemoveChecked<T>::CleanType CleanType; |
| static const CleanType DefaultValue = 0; |
| }; |
| |
| template <typename T> struct RemoveChecked<Checked<T, RecordOverflow> > { |
| typedef typename RemoveChecked<T>::CleanType CleanType; |
| static const CleanType DefaultValue = 0; |
| }; |
| |
| // The ResultBase and SignednessSelector are used to workaround typeof not being |
| // available in MSVC |
| template <typename U, typename V, bool uIsBigger = (sizeof(U) > sizeof(V)), bool sameSize = (sizeof(U) == sizeof(V))> struct ResultBase; |
| template <typename U, typename V> struct ResultBase<U, V, true, false> { |
| typedef U ResultType; |
| }; |
| |
| template <typename U, typename V> struct ResultBase<U, V, false, false> { |
| typedef V ResultType; |
| }; |
| |
| template <typename U> struct ResultBase<U, U, false, true> { |
| typedef U ResultType; |
| }; |
| |
| template <typename U, typename V, bool uIsSigned = std::numeric_limits<U>::is_signed, bool vIsSigned = std::numeric_limits<V>::is_signed> struct SignednessSelector; |
| template <typename U, typename V> struct SignednessSelector<U, V, true, true> { |
| typedef U ResultType; |
| }; |
| |
| template <typename U, typename V> struct SignednessSelector<U, V, false, false> { |
| typedef U ResultType; |
| }; |
| |
| template <typename U, typename V> struct SignednessSelector<U, V, true, false> { |
| typedef V ResultType; |
| }; |
| |
| template <typename U, typename V> struct SignednessSelector<U, V, false, true> { |
| typedef U ResultType; |
| }; |
| |
| template <typename U, typename V> struct ResultBase<U, V, false, true> { |
| typedef typename SignednessSelector<U, V>::ResultType ResultType; |
| }; |
| |
| template <typename U, typename V> struct Result : ResultBase<typename RemoveChecked<U>::CleanType, typename RemoveChecked<V>::CleanType> { |
| }; |
| |
| template <typename LHS, typename RHS, typename ResultType = typename Result<LHS, RHS>::ResultType, |
| bool lhsSigned = std::numeric_limits<LHS>::is_signed, bool rhsSigned = std::numeric_limits<RHS>::is_signed> struct ArithmeticOperations; |
| |
| template <typename LHS, typename RHS, typename ResultType> struct ArithmeticOperations<LHS, RHS, ResultType, true, true> { |
| // LHS and RHS are signed types |
| |
| // Helper function |
| static inline bool signsMatch(LHS lhs, RHS rhs) |
| { |
| return (lhs ^ rhs) >= 0; |
| } |
| |
| static inline bool add(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| if (signsMatch(lhs, rhs)) { |
| if (lhs >= 0) { |
| if ((std::numeric_limits<ResultType>::max() - rhs) < lhs) |
| return false; |
| } else { |
| ResultType temp = lhs - std::numeric_limits<ResultType>::min(); |
| if (rhs < -temp) |
| return false; |
| } |
| } // if the signs do not match this operation can't overflow |
| result = lhs + rhs; |
| return true; |
| } |
| |
| static inline bool sub(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| if (!signsMatch(lhs, rhs)) { |
| if (lhs >= 0) { |
| if (lhs > std::numeric_limits<ResultType>::max() + rhs) |
| return false; |
| } else { |
| if (rhs > std::numeric_limits<ResultType>::max() + lhs) |
| return false; |
| } |
| } // if the signs match this operation can't overflow |
| result = lhs - rhs; |
| return true; |
| } |
| |
| static inline bool multiply(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| if (signsMatch(lhs, rhs)) { |
| if (lhs >= 0) { |
| if (lhs && (std::numeric_limits<ResultType>::max() / lhs) < rhs) |
| return false; |
| } else { |
| if (static_cast<ResultType>(lhs) == std::numeric_limits<ResultType>::min() || static_cast<ResultType>(rhs) == std::numeric_limits<ResultType>::min()) |
| return false; |
| if ((std::numeric_limits<ResultType>::max() / -lhs) < -rhs) |
| return false; |
| } |
| } else { |
| if (lhs < 0) { |
| if (rhs && lhs < (std::numeric_limits<ResultType>::min() / rhs)) |
| return false; |
| } else { |
| if (lhs && rhs < (std::numeric_limits<ResultType>::min() / lhs)) |
| return false; |
| } |
| } |
| result = lhs * rhs; |
| return true; |
| } |
| |
| static inline bool equals(LHS lhs, RHS rhs) { return lhs == rhs; } |
| |
| }; |
| |
| template <typename LHS, typename RHS, typename ResultType> struct ArithmeticOperations<LHS, RHS, ResultType, false, false> { |
| // LHS and RHS are unsigned types so bounds checks are nice and easy |
| static inline bool add(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| ResultType temp = lhs + rhs; |
| if (temp < lhs) |
| return false; |
| result = temp; |
| return true; |
| } |
| |
| static inline bool sub(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| ResultType temp = lhs - rhs; |
| if (temp > lhs) |
| return false; |
| result = temp; |
| return true; |
| } |
| |
| static inline bool multiply(LHS lhs, RHS rhs, ResultType& result) WARN_UNUSED_RETURN |
| { |
| ResultType temp = lhs * rhs; |
| if (temp < lhs) |
| return false; |
| result = temp; |
| return true; |
| } |
| |
| static inline bool equals(LHS lhs, RHS rhs) { return lhs == rhs; } |
| |
| }; |
| |
| template <typename ResultType> struct ArithmeticOperations<int, unsigned, ResultType, true, false> { |
| static inline bool add(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| int64_t temp = lhs + rhs; |
| if (temp < std::numeric_limits<ResultType>::min()) |
| return false; |
| if (temp > std::numeric_limits<ResultType>::max()) |
| return false; |
| result = static_cast<ResultType>(temp); |
| return true; |
| } |
| |
| static inline bool sub(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| int64_t temp = lhs - rhs; |
| if (temp < std::numeric_limits<ResultType>::min()) |
| return false; |
| if (temp > std::numeric_limits<ResultType>::max()) |
| return false; |
| result = static_cast<ResultType>(temp); |
| return true; |
| } |
| |
| static inline bool multiply(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| int64_t temp = lhs * rhs; |
| if (temp < std::numeric_limits<ResultType>::min()) |
| return false; |
| if (temp > std::numeric_limits<ResultType>::max()) |
| return false; |
| result = static_cast<ResultType>(temp); |
| return true; |
| } |
| |
| static inline bool equals(int lhs, unsigned rhs) |
| { |
| return static_cast<int64_t>(lhs) == static_cast<int64_t>(rhs); |
| } |
| }; |
| |
| template <typename ResultType> struct ArithmeticOperations<unsigned, int, ResultType, false, true> { |
| static inline bool add(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| return ArithmeticOperations<int, unsigned, ResultType>::add(rhs, lhs, result); |
| } |
| |
| static inline bool sub(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| return ArithmeticOperations<int, unsigned, ResultType>::sub(lhs, rhs, result); |
| } |
| |
| static inline bool multiply(int64_t lhs, int64_t rhs, ResultType& result) |
| { |
| return ArithmeticOperations<int, unsigned, ResultType>::multiply(rhs, lhs, result); |
| } |
| |
| static inline bool equals(unsigned lhs, int rhs) |
| { |
| return ArithmeticOperations<int, unsigned, ResultType>::equals(rhs, lhs); |
| } |
| }; |
| |
| template <typename U, typename V, typename R> static inline bool safeAdd(U lhs, V rhs, R& result) |
| { |
| return ArithmeticOperations<U, V, R>::add(lhs, rhs, result); |
| } |
| |
| template <typename U, typename V, typename R> static inline bool safeSub(U lhs, V rhs, R& result) |
| { |
| return ArithmeticOperations<U, V, R>::sub(lhs, rhs, result); |
| } |
| |
| template <typename U, typename V, typename R> static inline bool safeMultiply(U lhs, V rhs, R& result) |
| { |
| return ArithmeticOperations<U, V, R>::multiply(lhs, rhs, result); |
| } |
| |
| template <typename U, typename V> static inline bool safeEquals(U lhs, V rhs) |
| { |
| return ArithmeticOperations<U, V>::equals(lhs, rhs); |
| } |
| |
| enum ResultOverflowedTag { ResultOverflowed }; |
| |
| // FIXME: Needed to workaround http://llvm.org/bugs/show_bug.cgi?id=10801 |
| static inline bool workAroundClangBug() { return true; } |
| |
| template <typename T, class OverflowHandler> class Checked : public OverflowHandler { |
| public: |
| template <typename _T, class _OverflowHandler> friend class Checked; |
| Checked() |
| : m_value(0) |
| { |
| } |
| |
| Checked(ResultOverflowedTag) |
| : m_value(0) |
| { |
| // FIXME: Remove this when clang fixes http://llvm.org/bugs/show_bug.cgi?id=10801 |
| if (workAroundClangBug()) |
| this->overflowed(); |
| } |
| |
| template <typename U> Checked(U value) |
| { |
| if (!isInBounds<T>(value)) |
| this->overflowed(); |
| m_value = static_cast<T>(value); |
| } |
| |
| template <typename V> Checked(const Checked<T, V>& rhs) |
| : m_value(rhs.m_value) |
| { |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| } |
| |
| template <typename U> Checked(const Checked<U, OverflowHandler>& rhs) |
| : OverflowHandler(rhs) |
| { |
| if (!isInBounds<T>(rhs.m_value)) |
| this->overflowed(); |
| m_value = static_cast<T>(rhs.m_value); |
| } |
| |
| template <typename U, typename V> Checked(const Checked<U, V>& rhs) |
| { |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| if (!isInBounds<T>(rhs.m_value)) |
| this->overflowed(); |
| m_value = static_cast<T>(rhs.m_value); |
| } |
| |
| const Checked& operator=(Checked rhs) |
| { |
| this->clearOverflow(); |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| m_value = static_cast<T>(rhs.m_value); |
| return *this; |
| } |
| |
| template <typename U> const Checked& operator=(U value) |
| { |
| return *this = Checked(value); |
| } |
| |
| template <typename U, typename V> const Checked& operator=(const Checked<U, V>& rhs) |
| { |
| return *this = Checked(rhs); |
| } |
| |
| // prefix |
| const Checked& operator++() |
| { |
| if (m_value == std::numeric_limits<T>::max()) |
| this->overflowed(); |
| m_value++; |
| return *this; |
| } |
| |
| const Checked& operator--() |
| { |
| if (m_value == std::numeric_limits<T>::min()) |
| this->overflowed(); |
| m_value--; |
| return *this; |
| } |
| |
| // postfix operators |
| const Checked operator++(int) |
| { |
| if (m_value == std::numeric_limits<T>::max()) |
| this->overflowed(); |
| return Checked(m_value++); |
| } |
| |
| const Checked operator--(int) |
| { |
| if (m_value == std::numeric_limits<T>::min()) |
| this->overflowed(); |
| return Checked(m_value--); |
| } |
| |
| // Boolean operators |
| bool operator!() const |
| { |
| if (this->hasOverflowed()) |
| CRASH(); |
| return !m_value; |
| } |
| |
| typedef void* (Checked::*UnspecifiedBoolType); |
| operator UnspecifiedBoolType*() const |
| { |
| if (this->hasOverflowed()) |
| CRASH(); |
| return (m_value) ? reinterpret_cast<UnspecifiedBoolType*>(1) : 0; |
| } |
| |
| // Value accessors. unsafeGet() will crash if there's been an overflow. |
| T unsafeGet() const |
| { |
| if (this->hasOverflowed()) |
| CRASH(); |
| return m_value; |
| } |
| |
| bool safeGet(T& value) const WARN_UNUSED_RETURN |
| { |
| value = m_value; |
| return this->hasOverflowed(); |
| } |
| |
| // Mutating assignment |
| template <typename U> const Checked operator+=(U rhs) |
| { |
| if (!safeAdd(m_value, rhs, m_value)) |
| this->overflowed(); |
| return *this; |
| } |
| |
| template <typename U> const Checked operator-=(U rhs) |
| { |
| if (!safeSub(m_value, rhs, m_value)) |
| this->overflowed(); |
| return *this; |
| } |
| |
| template <typename U> const Checked operator*=(U rhs) |
| { |
| if (!safeMultiply(m_value, rhs, m_value)) |
| this->overflowed(); |
| return *this; |
| } |
| |
| const Checked operator*=(double rhs) |
| { |
| double result = rhs * m_value; |
| // Handle +/- infinity and NaN |
| if (!(std::numeric_limits<T>::min() <= result && std::numeric_limits<T>::max() >= result)) |
| this->overflowed(); |
| m_value = (T)result; |
| return *this; |
| } |
| |
| const Checked operator*=(float rhs) |
| { |
| return *this *= (double)rhs; |
| } |
| |
| template <typename U, typename V> const Checked operator+=(Checked<U, V> rhs) |
| { |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| return *this += rhs.m_value; |
| } |
| |
| template <typename U, typename V> const Checked operator-=(Checked<U, V> rhs) |
| { |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| return *this -= rhs.m_value; |
| } |
| |
| template <typename U, typename V> const Checked operator*=(Checked<U, V> rhs) |
| { |
| if (rhs.hasOverflowed()) |
| this->overflowed(); |
| return *this *= rhs.m_value; |
| } |
| |
| // Equality comparisons |
| template <typename V> bool operator==(Checked<T, V> rhs) |
| { |
| return unsafeGet() == rhs.unsafeGet(); |
| } |
| |
| template <typename U> bool operator==(U rhs) |
| { |
| if (this->hasOverflowed()) |
| this->overflowed(); |
| return safeEquals(m_value, rhs); |
| } |
| |
| template <typename U, typename V> const Checked operator==(Checked<U, V> rhs) |
| { |
| return unsafeGet() == Checked(rhs.unsafeGet()); |
| } |
| |
| template <typename U> bool operator!=(U rhs) |
| { |
| return !(*this == rhs); |
| } |
| |
| private: |
| // Disallow implicit conversion of floating point to integer types |
| Checked(float); |
| Checked(double); |
| void operator=(float); |
| void operator=(double); |
| void operator+=(float); |
| void operator+=(double); |
| void operator-=(float); |
| void operator-=(double); |
| T m_value; |
| }; |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator+(Checked<U, OverflowHandler> lhs, Checked<V, OverflowHandler> rhs) |
| { |
| U x = 0; |
| V y = 0; |
| bool overflowed = lhs.safeGet(x) || rhs.safeGet(y); |
| typename Result<U, V>::ResultType result = 0; |
| overflowed |= !safeAdd(x, y, result); |
| if (overflowed) |
| return ResultOverflowed; |
| return result; |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator-(Checked<U, OverflowHandler> lhs, Checked<V, OverflowHandler> rhs) |
| { |
| U x = 0; |
| V y = 0; |
| bool overflowed = lhs.safeGet(x) || rhs.safeGet(y); |
| typename Result<U, V>::ResultType result = 0; |
| overflowed |= !safeSub(x, y, result); |
| if (overflowed) |
| return ResultOverflowed; |
| return result; |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator*(Checked<U, OverflowHandler> lhs, Checked<V, OverflowHandler> rhs) |
| { |
| U x = 0; |
| V y = 0; |
| bool overflowed = lhs.safeGet(x) || rhs.safeGet(y); |
| typename Result<U, V>::ResultType result = 0; |
| overflowed |= !safeMultiply(x, y, result); |
| if (overflowed) |
| return ResultOverflowed; |
| return result; |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator+(Checked<U, OverflowHandler> lhs, V rhs) |
| { |
| return lhs + Checked<V, OverflowHandler>(rhs); |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator-(Checked<U, OverflowHandler> lhs, V rhs) |
| { |
| return lhs - Checked<V, OverflowHandler>(rhs); |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator*(Checked<U, OverflowHandler> lhs, V rhs) |
| { |
| return lhs * Checked<V, OverflowHandler>(rhs); |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator+(U lhs, Checked<V, OverflowHandler> rhs) |
| { |
| return Checked<U, OverflowHandler>(lhs) + rhs; |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator-(U lhs, Checked<V, OverflowHandler> rhs) |
| { |
| return Checked<U, OverflowHandler>(lhs) - rhs; |
| } |
| |
| template <typename U, typename V, typename OverflowHandler> static inline Checked<typename Result<U, V>::ResultType, OverflowHandler> operator*(U lhs, Checked<V, OverflowHandler> rhs) |
| { |
| return Checked<U, OverflowHandler>(lhs) * rhs; |
| } |
| |
| } |
| |
| using WTF::Checked; |
| using WTF::RecordOverflow; |
| |
| #endif |