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// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
// SPDX-FileCopyrightInfo: Copyright © DUNE Project contributors, see file LICENSE.md in module root
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
#include <iostream>
#include <algorithm>
#include <dune/common/densevector.hh>
#include <dune/common/fvector.hh>
#include <dune/common/fmatrix.hh>
#include <dune/common/exceptions.hh>
//! @file
/**
* This test tests for a regression, where `std::is_assignable` would return
* `true` for certain assignments, but it was not actually possible to
* instantiate those assignments. In the fix `std::is_assignable` was fixed
* to report false, and that is what is checked now.
*/
template<class Component, std::size_t Dim >
class MyVector;
namespace Dune
{
template<class Component, std::size_t Dim>
struct DenseMatVecTraits< MyVector<Component, Dim> >
{
using derived_type = MyVector<Component, Dim>;
using value_type = Component;
using size_type = std::size_t;
};
template<class Component, std::size_t Dim, int Size>
struct IsFieldVectorSizeCorrect<MyVector<Component, Dim>, Size>
: std::integral_constant<bool, Dim == Size>
{};
}
template<class Component, std::size_t Dim >
class MyVector : public Dune::DenseVector< MyVector<Component, Dim> >
{
public:
static constexpr std::size_t size () { return Dim; }
Component& operator[] ( std::size_t i ) { return data_; }
const Component& operator[] ( std::size_t i ) const { return data_; }
protected:
Component data_;
};
int main()
{
try
{
// Pure 1d case. Here OuterMV is assignable to MiddleFV as the the
// 1d FieldVector implements a type-case to the underlying
// field. This is expected behaviour.
{
using InnerFV = Dune::FieldVector<double, 1>;
using MiddleFV = Dune::FieldVector<InnerFV, 1>;
using OuterFV = Dune::FieldVector<MiddleFV, 1>;
using MiddleMV = MyVector<InnerFV, 1>;
using OuterMV = MyVector<MiddleMV, 1>;
MiddleFV mfv;
OuterMV mv;
OuterFV fv;
static_assert(std::is_convertible<OuterMV, OuterFV>::value,
"DenseVectors should be convertible.");
fv = mv;
static_assert(std::is_assignable<MiddleFV&, OuterMV>::value,
"Reduced assignability detected.");
mfv = mv;
}
// The following would trigger a problem in the DenseVector
// operator=() which was cured by first checking whether the
// value_types are assignable.
{
using InnerFV = Dune::FieldVector<double, 2>;
using MiddleFV = Dune::FieldVector<InnerFV, 1>;
using OuterFV = Dune::FieldVector<MiddleFV, 1>;
using MiddleMV = MyVector<InnerFV, 1>;
using OuterMV = MyVector<MiddleMV, 1>;
// MiddleFV mfv;
OuterMV mv;
OuterFV fv;
static_assert(std::is_convertible<OuterMV, OuterFV>::value,
"DenseVectors should be convertible.");
fv = mv;
// before the fix, `is_assignable` returned `true`,
static_assert(!std::is_assignable<MiddleFV&, OuterMV>::value,
"Inconsistent assignability detected.");
// mfv = mv; // <- but this assignment failed instantiation
}
{
using InnerFV = Dune::FieldMatrix<double, 2, 2>;
using MiddleFV = Dune::FieldVector<InnerFV, 1>;
using OuterFV = Dune::FieldVector<MiddleFV, 1>;
using MiddleMV = MyVector<InnerFV, 1>;
using OuterMV = MyVector<MiddleMV, 1>;
// MiddleFV mfv;
OuterMV mv;
OuterFV fv;
static_assert(std::is_assignable<OuterFV, OuterMV>::value,
"DenseVectors should be assignable.");
fv = mv;
// before the fix, `is_assignable` returned `true`,
static_assert(!std::is_assignable<MiddleFV&, OuterMV>::value,
"Inconsistent assignability detected.");
// mfv = mv; // <- but this assignment failed instantiation
}
return 0;
} catch (Dune::Exception& e) {
std::cerr << e << std::endl;
return 1;
} catch (...) {
std::cerr << "Generic exception!" << std::endl;
return 2;
}
}
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