// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2009 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef EIGEN_META_H
#define EIGEN_META_H
namespace Eigen {
namespace internal {
/** \internal
* \file Meta.h
* This file contains generic metaprogramming classes which are not specifically related to Eigen.
* \note In case you wonder, yes we're aware that Boost already provides all these features,
* we however don't want to add a dependency to Boost.
*/
struct true_type { enum { value = 1 }; };
struct false_type { enum { value = 0 }; };
template<bool Condition, typename Then, typename Else>
struct conditional { typedef Then type; };
template<typename Then, typename Else>
struct conditional <false, Then, Else> { typedef Else type; };
template<typename T, typename U> struct is_same { enum { value = 0 }; };
template<typename T> struct is_same<T,T> { enum { value = 1 }; };
template<typename T> struct remove_reference { typedef T type; };
template<typename T> struct remove_reference<T&> { typedef T type; };
template<typename T> struct remove_pointer { typedef T type; };
template<typename T> struct remove_pointer<T*> { typedef T type; };
template<typename T> struct remove_pointer<T*const> { typedef T type; };
template <class T> struct remove_const { typedef T type; };
template <class T> struct remove_const<const T> { typedef T type; };
template <class T> struct remove_const<const T[]> { typedef T type[]; };
template <class T, unsigned int Size> struct remove_const<const T[Size]> { typedef T type[Size]; };
template<typename T> struct remove_all { typedef T type; };
template<typename T> struct remove_all<const T> { typedef typename remove_all<T>::type type; };
template<typename T> struct remove_all<T const&> { typedef typename remove_all<T>::type type; };
template<typename T> struct remove_all<T&> { typedef typename remove_all<T>::type type; };
template<typename T> struct remove_all<T const*> { typedef typename remove_all<T>::type type; };
template<typename T> struct remove_all<T*> { typedef typename remove_all<T>::type type; };
template<typename T> struct is_arithmetic { enum { value = false }; };
template<> struct is_arithmetic<float> { enum { value = true }; };
template<> struct is_arithmetic<double> { enum { value = true }; };
template<> struct is_arithmetic<long double> { enum { value = true }; };
template<> struct is_arithmetic<bool> { enum { value = true }; };
template<> struct is_arithmetic<char> { enum { value = true }; };
template<> struct is_arithmetic<signed char> { enum { value = true }; };
template<> struct is_arithmetic<unsigned char> { enum { value = true }; };
template<> struct is_arithmetic<signed short> { enum { value = true }; };
template<> struct is_arithmetic<unsigned short>{ enum { value = true }; };
template<> struct is_arithmetic<signed int> { enum { value = true }; };
template<> struct is_arithmetic<unsigned int> { enum { value = true }; };
template<> struct is_arithmetic<signed long> { enum { value = true }; };
template<> struct is_arithmetic<unsigned long> { enum { value = true }; };
template <typename T> struct add_const { typedef const T type; };
template <typename T> struct add_const<T&> { typedef T& type; };
template <typename T> struct is_const { enum { value = 0 }; };
template <typename T> struct is_const<T const> { enum { value = 1 }; };
template<typename T> struct add_const_on_value_type { typedef const T type; };
template<typename T> struct add_const_on_value_type<T&> { typedef T const& type; };
template<typename T> struct add_const_on_value_type<T*> { typedef T const* type; };
template<typename T> struct add_const_on_value_type<T* const> { typedef T const* const type; };
template<typename T> struct add_const_on_value_type<T const* const> { typedef T const* const type; };
/** \internal Allows to enable/disable an overload
* according to a compile time condition.
*/
template<bool Condition, typename T> struct enable_if;
template<typename T> struct enable_if<true,T>
{ typedef T type; };
/** \internal
* A base class do disable default copy ctor and copy assignement operator.
*/
class noncopyable
{
noncopyable(const noncopyable&);
const noncopyable& operator=(const noncopyable&);
protected:
noncopyable() {}
~noncopyable() {}
};
/** \internal
* Convenient struct to get the result type of a unary or binary functor.
*
* It supports both the current STL mechanism (using the result_type member) as well as
* upcoming next STL generation (using a templated result member).
* If none of these members is provided, then the type of the first argument is returned. FIXME, that behavior is a pretty bad hack.
*/
template<typename T> struct result_of {};
struct has_none {int a[1];};
struct has_std_result_type {int a[2];};
struct has_tr1_result {int a[3];};
template<typename Func, typename ArgType, int SizeOf=sizeof(has_none)>
struct unary_result_of_select {typedef ArgType type;};
template<typename Func, typename ArgType>
struct unary_result_of_select<Func, ArgType, sizeof(has_std_result_type)> {typedef typename Func::result_type type;};
template<typename Func, typename ArgType>
struct unary_result_of_select<Func, ArgType, sizeof(has_tr1_result)> {typedef typename Func::template result<Func(ArgType)>::type type;};
template<typename Func, typename ArgType>
struct result_of<Func(ArgType)> {
template<typename T>
static has_std_result_type testFunctor(T const *, typename T::result_type const * = 0);
template<typename T>
static has_tr1_result testFunctor(T const *, typename T::template result<T(ArgType)>::type const * = 0);
static has_none testFunctor(...);
// note that the following indirection is needed for gcc-3.3
enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))};
typedef typename unary_result_of_select<Func, ArgType, FunctorType>::type type;
};
template<typename Func, typename ArgType0, typename ArgType1, int SizeOf=sizeof(has_none)>
struct binary_result_of_select {typedef ArgType0 type;};
template<typename Func, typename ArgType0, typename ArgType1>
struct binary_result_of_select<Func, ArgType0, ArgType1, sizeof(has_std_result_type)>
{typedef typename Func::result_type type;};
template<typename Func, typename ArgType0, typename ArgType1>
struct binary_result_of_select<Func, ArgType0, ArgType1, sizeof(has_tr1_result)>
{typedef typename Func::template result<Func(ArgType0,ArgType1)>::type type;};
template<typename Func, typename ArgType0, typename ArgType1>
struct result_of<Func(ArgType0,ArgType1)> {
template<typename T>
static has_std_result_type testFunctor(T const *, typename T::result_type const * = 0);
template<typename T>
static has_tr1_result testFunctor(T const *, typename T::template result<T(ArgType0,ArgType1)>::type const * = 0);
static has_none testFunctor(...);
// note that the following indirection is needed for gcc-3.3
enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))};
typedef typename binary_result_of_select<Func, ArgType0, ArgType1, FunctorType>::type type;
};
/** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer.
* Usage example: \code meta_sqrt<1023>::ret \endcode
*/
template<int Y,
int InfX = 0,
int SupX = ((Y==1) ? 1 : Y/2),
bool Done = ((SupX-InfX)<=1 ? true : ((SupX*SupX <= Y) && ((SupX+1)*(SupX+1) > Y))) >
// use ?: instead of || just to shut up a stupid gcc 4.3 warning
class meta_sqrt
{
enum {
MidX = (InfX+SupX)/2,
TakeInf = MidX*MidX > Y ? 1 : 0,
NewInf = int(TakeInf) ? InfX : int(MidX),
NewSup = int(TakeInf) ? int(MidX) : SupX
};
public:
enum { ret = meta_sqrt<Y,NewInf,NewSup>::ret };
};
template<int Y, int InfX, int SupX>
class meta_sqrt<Y, InfX, SupX, true> { public: enum { ret = (SupX*SupX <= Y) ? SupX : InfX }; };
/** \internal determines whether the product of two numeric types is allowed and what the return type is */
template<typename T, typename U> struct scalar_product_traits
{
enum { Defined = 0 };
};
template<typename T> struct scalar_product_traits<T,T>
{
enum {
// Cost = NumTraits<T>::MulCost,
Defined = 1
};
typedef T ReturnType;
};
template<typename T> struct scalar_product_traits<T,std::complex<T> >
{
enum {
// Cost = 2*NumTraits<T>::MulCost,
Defined = 1
};
typedef std::complex<T> ReturnType;
};
template<typename T> struct scalar_product_traits<std::complex<T>, T>
{
enum {
// Cost = 2*NumTraits<T>::MulCost,
Defined = 1
};
typedef std::complex<T> ReturnType;
};
// FIXME quick workaround around current limitation of result_of
// template<typename Scalar, typename ArgType0, typename ArgType1>
// struct result_of<scalar_product_op<Scalar>(ArgType0,ArgType1)> {
// typedef typename scalar_product_traits<typename remove_all<ArgType0>::type, typename remove_all<ArgType1>::type>::ReturnType type;
// };
template<typename T> struct is_diagonal
{ enum { ret = false }; };
template<typename T> struct is_diagonal<DiagonalBase<T> >
{ enum { ret = true }; };
template<typename T> struct is_diagonal<DiagonalWrapper<T> >
{ enum { ret = true }; };
template<typename T, int S> struct is_diagonal<DiagonalMatrix<T,S> >
{ enum { ret = true }; };
} // end namespace internal
} // end namespace Eigen
#endif // EIGEN_META_H