Move base to DEPS

base/numerics/safe_conversions.h

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_NUMERICS_SAFE_CONVERSIONS_H_
-#define BASE_NUMERICS_SAFE_CONVERSIONS_H_
-
-#include <limits>
-
-#include "base/logging.h"
-#include "base/numerics/safe_conversions_impl.h"
-
-namespace base {
-
-// Convenience function that returns true if the supplied value is in range
-// for the destination type.
-template <typename Dst, typename Src>
-inline bool IsValueInRangeForNumericType(Src value) {
-  return internal::DstRangeRelationToSrcRange<Dst>(value) ==
-         internal::RANGE_VALID;
-}
-
-// checked_cast<> is analogous to static_cast<> for numeric types,
-// except that it CHECKs that the specified numeric conversion will not
-// overflow or underflow. NaN source will always trigger a CHECK.
-template <typename Dst, typename Src>
-inline Dst checked_cast(Src value) {
-  CHECK(IsValueInRangeForNumericType<Dst>(value));
-  return static_cast<Dst>(value);
-}
-
-// saturated_cast<> is analogous to static_cast<> for numeric types, except
-// that the specified numeric conversion will saturate rather than overflow or
-// underflow. NaN assignment to an integral will trigger a CHECK condition.
-template <typename Dst, typename Src>
-inline Dst saturated_cast(Src value) {
-  // Optimization for floating point values, which already saturate.
-  if (std::numeric_limits<Dst>::is_iec559)
-    return static_cast<Dst>(value);
-
-  switch (internal::DstRangeRelationToSrcRange<Dst>(value)) {
-    case internal::RANGE_VALID:
-      return static_cast<Dst>(value);
-
-    case internal::RANGE_UNDERFLOW:
-      return std::numeric_limits<Dst>::min();
-
-    case internal::RANGE_OVERFLOW:
-      return std::numeric_limits<Dst>::max();
-
-    // Should fail only on attempting to assign NaN to a saturated integer.
-    case internal::RANGE_INVALID:
-      CHECK(false);
-      return std::numeric_limits<Dst>::max();
-  }
-
-  NOTREACHED();
-  return static_cast<Dst>(value);
-}
-
-// strict_cast<> is analogous to static_cast<> for numeric types, except that
-// it will cause a compile failure if the destination type is not large enough
-// to contain any value in the source type. It performs no runtime checking.
-template <typename Dst, typename Src>
-inline Dst strict_cast(Src value) {
-  static_assert(std::numeric_limits<Src>::is_specialized,
-                "Argument must be numeric.");
-  static_assert(std::numeric_limits<Dst>::is_specialized,
-                "Result must be numeric.");
-  static_assert((internal::StaticDstRangeRelationToSrcRange<Dst, Src>::value ==
-                 internal::NUMERIC_RANGE_CONTAINED),
-                "The numeric conversion is out of range for this type. You "
-                "should probably use one of the following conversion "
-                "mechanisms on the value you want to pass:\n"
-                "- base::checked_cast\n"
-                "- base::saturated_cast\n"
-                "- base::CheckedNumeric");
-
-  return static_cast<Dst>(value);
-}
-
-// StrictNumeric implements compile time range checking between numeric types by
-// wrapping assignment operations in a strict_cast. This class is intended to be
-// used for function arguments and return types, to ensure the destination type
-// can always contain the source type. This is essentially the same as enforcing
-// -Wconversion in gcc and C4302 warnings on MSVC, but it can be applied
-// incrementally at API boundaries, making it easier to convert code so that it
-// compiles cleanly with truncation warnings enabled.
-// This template should introduce no runtime overhead, but it also provides no
-// runtime checking of any of the associated mathematical operations. Use
-// CheckedNumeric for runtime range checks of tha actual value being assigned.
-template <typename T>
-class StrictNumeric {
- public:
-  typedef T type;
-
-  StrictNumeric() : value_(0) {}
-
-  // Copy constructor.
-  template <typename Src>
-  StrictNumeric(const StrictNumeric<Src>& rhs)
-      : value_(strict_cast<T>(rhs.value_)) {}
-
-  // This is not an explicit constructor because we implicitly upgrade regular
-  // numerics to StrictNumerics to make them easier to use.
-  template <typename Src>
-  StrictNumeric(Src value)
-      : value_(strict_cast<T>(value)) {}
-
-  // The numeric cast operator basically handles all the magic.
-  template <typename Dst>
-  operator Dst() const {
-    return strict_cast<Dst>(value_);
-  }
-
- private:
-  T value_;
-};
-
-// Explicitly make a shorter size_t typedef for convenience.
-typedef StrictNumeric<size_t> SizeT;
-
-}  // namespace base
-
-#endif  // BASE_NUMERICS_SAFE_CONVERSIONS_H_