diff options
| -rw-r--r-- | Eigen/src/Core/IO.h | 24 | ||||
| -rw-r--r-- | Eigen/src/Core/NumTraits.h | 41 |
2 files changed, 46 insertions, 19 deletions
diff --git a/Eigen/src/Core/IO.h b/Eigen/src/Core/IO.h index 8c794837f..94e00f58b 100644 --- a/Eigen/src/Core/IO.h +++ b/Eigen/src/Core/IO.h @@ -125,32 +125,18 @@ DenseBase<Derived>::format(const IOFormat& fmt) const namespace internal { -template<typename Scalar, bool IsInteger> -struct significant_decimals_default_impl -{ - typedef typename NumTraits<Scalar>::Real RealScalar; - static inline int run() - { - using std::ceil; - using std::log10; - return cast<RealScalar,int>(ceil(-log10(NumTraits<RealScalar>::epsilon()))); - } -}; - +// NOTE: This helper is kept for backward compatibility with previous code specializing +// this internal::significant_decimals_impl structure. In the future we should directly +// call digits10() which has been introduced in July 2016 in 3.3. template<typename Scalar> -struct significant_decimals_default_impl<Scalar, true> +struct significant_decimals_impl { static inline int run() { - return 0; + return NumTraits<Scalar>::digits10(); } }; -template<typename Scalar> -struct significant_decimals_impl - : significant_decimals_default_impl<Scalar, NumTraits<Scalar>::IsInteger> -{}; - /** \internal * print the matrix \a _m to the output stream \a s using the output format \a fmt */ template<typename Derived> diff --git a/Eigen/src/Core/NumTraits.h b/Eigen/src/Core/NumTraits.h index 03f64a8e9..a688df504 100644 --- a/Eigen/src/Core/NumTraits.h +++ b/Eigen/src/Core/NumTraits.h @@ -12,6 +12,37 @@ namespace Eigen { +namespace internal { + +// default implementation of digits10(), based on numeric_limits if specialized, +// 0 for integer types, and log10(epsilon()) otherwise. +template< typename T, + bool use_numeric_limits = std::numeric_limits<T>::is_specialized, + bool is_integer = NumTraits<T>::IsInteger> +struct default_digits10_impl +{ + static int run() { return std::numeric_limits<T>::digits10; } +}; + +template<typename T> +struct default_digits10_impl<T,false,false> // Floating point +{ + static int run() { + using std::log10; + using std::ceil; + typedef typename NumTraits<T>::Real Real; + return int(ceil(-log10(NumTraits<Real>::epsilon()))); + } +}; + +template<typename T> +struct default_digits10_impl<T,false,true> // Integer +{ + static int run() { return 0; } +}; + +} // end namespace internal + /** \class NumTraits * \ingroup Core_Module * @@ -48,6 +79,9 @@ namespace Eigen { * \li A dummy_precision() function returning a weak epsilon value. It is mainly used as a default * value by the fuzzy comparison operators. * \li highest() and lowest() functions returning the highest and lowest possible values respectively. + * \li digits10() function returning the number of decimal digits that can be represented without change. This is + * the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits10">std::numeric_limits<T>::digits10</a> + * which is used as the default implementation if specialized. */ template<typename T> struct GenericNumTraits @@ -93,6 +127,13 @@ template<typename T> struct GenericNumTraits { return numext::numeric_limits<T>::epsilon(); } + + EIGEN_DEVICE_FUNC + static inline int digits10() + { + return internal::default_digits10_impl<T>::run(); + } + EIGEN_DEVICE_FUNC static inline Real dummy_precision() { |