test/meta.cpp

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// 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/.

#include "main.h"

template<typename From, typename To>
bool check_is_convertible(const From&, const To&)
{
  return internal::is_convertible<From,To>::value;
}

struct FooReturnType {
  typedef int ReturnType;
};

struct MyInterface {
  virtual void func() = 0;
  virtual ~MyInterface() {}
};
struct MyImpl : public MyInterface {
  void func() {}
};

EIGEN_DECLARE_TEST(meta)
{
  VERIFY((internal::conditional<(3<4),internal::true_type, internal::false_type>::type::value));
  VERIFY(( internal::is_same<float,float>::value));
  VERIFY((!internal::is_same<float,double>::value));
  VERIFY((!internal::is_same<float,float&>::value));
  VERIFY((!internal::is_same<float,const float&>::value));
  
  VERIFY(( internal::is_same<float,internal::remove_all<const float&>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<const float*>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<const float*&>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<float**>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<float**&>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<float* const *&>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_all<float* const>::type >::value));

  // test add_const
  VERIFY(( internal::is_same< internal::add_const<float>::type, const float >::value));
  VERIFY(( internal::is_same< internal::add_const<float*>::type, float* const>::value));
  VERIFY(( internal::is_same< internal::add_const<float const*>::type, float const* const>::value));
  VERIFY(( internal::is_same< internal::add_const<float&>::type, float& >::value));

  // test remove_const
  VERIFY(( internal::is_same< internal::remove_const<float const* const>::type, float const* >::value));
  VERIFY(( internal::is_same< internal::remove_const<float const*>::type, float const* >::value));
  VERIFY(( internal::is_same< internal::remove_const<float* const>::type, float* >::value));

  // test add_const_on_value_type
  VERIFY(( internal::is_same< internal::add_const_on_value_type<float&>::type, float const& >::value));
  VERIFY(( internal::is_same< internal::add_const_on_value_type<float*>::type, float const* >::value));

  VERIFY(( internal::is_same< internal::add_const_on_value_type<float>::type, const float >::value));
  VERIFY(( internal::is_same< internal::add_const_on_value_type<const float>::type, const float >::value));

  VERIFY(( internal::is_same< internal::add_const_on_value_type<const float* const>::type, const float* const>::value));
  VERIFY(( internal::is_same< internal::add_const_on_value_type<float* const>::type, const float* const>::value));
  
  VERIFY(( internal::is_same<float,internal::remove_reference<float&>::type >::value));
  VERIFY(( internal::is_same<const float,internal::remove_reference<const float&>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_pointer<float*>::type >::value));
  VERIFY(( internal::is_same<const float,internal::remove_pointer<const float*>::type >::value));
  VERIFY(( internal::is_same<float,internal::remove_pointer<float* const >::type >::value));
  

  // is_convertible
  STATIC_CHECK(( internal::is_convertible<float,double>::value ));
  STATIC_CHECK(( internal::is_convertible<int,double>::value ));
  STATIC_CHECK(( internal::is_convertible<int, short>::value ));
  STATIC_CHECK(( internal::is_convertible<short, int>::value ));
  STATIC_CHECK(( internal::is_convertible<double,int>::value ));
  STATIC_CHECK(( internal::is_convertible<double,std::complex<double> >::value ));
  STATIC_CHECK((!internal::is_convertible<std::complex<double>,double>::value ));
  STATIC_CHECK(( internal::is_convertible<Array33f,Matrix3f>::value ));
  STATIC_CHECK(( internal::is_convertible<Matrix3f&,Matrix3f>::value ));
  STATIC_CHECK(( internal::is_convertible<Matrix3f&,Matrix3f&>::value ));
  STATIC_CHECK(( internal::is_convertible<Matrix3f&,const Matrix3f&>::value ));
  STATIC_CHECK(( internal::is_convertible<const Matrix3f&,Matrix3f>::value ));
  STATIC_CHECK(( internal::is_convertible<const Matrix3f&,const Matrix3f&>::value ));
  STATIC_CHECK((!internal::is_convertible<const Matrix3f&,Matrix3f&>::value ));
  STATIC_CHECK((!internal::is_convertible<const Matrix3f,Matrix3f&>::value ));
  STATIC_CHECK(( internal::is_convertible<Matrix3f,Matrix3f&>::value )); // std::is_convertible returns false here though Matrix3f from; Matrix3f& to = from; is valid.
  //STATIC_CHECK((!internal::is_convertible<Matrix3f,Matrix3d>::value )); //does not work because the conversion is prevented by a static assertion
  STATIC_CHECK((!internal::is_convertible<Array33f,int>::value ));
  STATIC_CHECK((!internal::is_convertible<MatrixXf,float>::value ));
  {
    float f;
    MatrixXf A, B;
    VectorXf a, b;
    VERIFY(( check_is_convertible(a.dot(b), f) ));
    VERIFY(( check_is_convertible(a.transpose()*b, f) ));
    VERIFY((!check_is_convertible(A*B, f) ));
    VERIFY(( check_is_convertible(A*B, A) ));
  }

  STATIC_CHECK(( !internal::is_convertible<MyInterface, MyImpl>::value ));
  #if (!EIGEN_COMP_GNUC_STRICT) || (EIGEN_GNUC_AT_LEAST(4,8))
  // GCC prior to 4.8 fails to compile this test:
  // error: cannot allocate an object of abstract type 'MyInterface'
  // In other word, it does not obey SFINAE.
  // Nevertheless, we don't really care about supporting abstract type as scalar type!
  STATIC_CHECK(( !internal::is_convertible<MyImpl, MyInterface>::value ));
  #endif
  STATIC_CHECK((  internal::is_convertible<MyImpl, const MyInterface&>::value ));
  {
    int i;
    VERIFY(( check_is_convertible(fix<3>(), i) ));
    VERIFY((!check_is_convertible(i, fix<DynamicIndex>()) ));
  }

  VERIFY((  internal::has_ReturnType<FooReturnType>::value ));
  VERIFY((  internal::has_ReturnType<ScalarBinaryOpTraits<int,int> >::value ));
  VERIFY(( !internal::has_ReturnType<MatrixXf>::value ));
  VERIFY(( !internal::has_ReturnType<int>::value ));
  
  VERIFY(internal::meta_sqrt<1>::ret == 1);
  #define VERIFY_META_SQRT(X) VERIFY(internal::meta_sqrt<X>::ret == int(std::sqrt(double(X))))
  VERIFY_META_SQRT(2);
  VERIFY_META_SQRT(3);
  VERIFY_META_SQRT(4);
  VERIFY_META_SQRT(5);
  VERIFY_META_SQRT(6);
  VERIFY_META_SQRT(8);
  VERIFY_META_SQRT(9);
  VERIFY_META_SQRT(15);
  VERIFY_META_SQRT(16);
  VERIFY_META_SQRT(17);
  VERIFY_META_SQRT(255);
  VERIFY_META_SQRT(256);
  VERIFY_META_SQRT(257);
  VERIFY_META_SQRT(1023);
  VERIFY_META_SQRT(1024);
  VERIFY_META_SQRT(1025);
}