我正在使用本征线性代数库,需要一个BiCGSTAB-solvers的向量。不幸的是,扩展这个向量是非常困难的。最小(非)工作示例是
#include <Eigen/Eigen>
int main() {
std::vector< Eigen::BiCGSTAB< Eigen::SparseMatrix< double > > > tmp;
tmp.emplace_back();
}并产生错误消息。
$ g++ -I/usr/include/eigen3 main.cpp
In file included from /usr/include/c++/12.2.0/vector:63,
from /usr/include/c++/12.2.0/functional:62,
from /usr/include/eigen3/Eigen/Core:85,
from /usr/include/eigen3/Eigen/Dense:1,
from /usr/include/eigen3/Eigen/Eigen:1,
from main.cpp:1:
/usr/include/c++/12.2.0/bits/stl_uninitialized.h: In instantiation of ‘constexpr bool std::__check_constructible() [with _ValueType = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&&]’:
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:182:4: required from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = move_iterator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*>; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*]’
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:372:37: required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, allocator<_Tp>&) [with _InputIterator = move_iterator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*>; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >]’
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:397:2: required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _Allocator = allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >]’
/usr/include/c++/12.2.0/bits/vector.tcc:487:3: required from ‘void std::vector<_Tp, _Alloc>::_M_realloc_insert(iterator, _Args&& ...) [with _Args = {}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; iterator = std::vector<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::iterator]’
/usr/include/c++/12.2.0/bits/vector.tcc:123:21: required from ‘std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; reference = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&]’
main.cpp:5:21: required from here
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:90:56: error: static assertion failed: result type must be constructible from input type
90 | static_assert(is_constructible<_ValueType, _Tp>::value,
| ^~~~~
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:90:56: note: ‘std::integral_constant<bool, false>::value’ evaluates to false尝试std::move更糟糕,即
#include <Eigen/Eigen>
#include <utility>
int main() {
std::vector< Eigen::BiCGSTAB< Eigen::SparseMatrix< double > > > tmp;
Eigen::BiCGSTAB< Eigen::SparseMatrix< double > > solver;
tmp.push_back( std::move( solver ) );
}导致错误消息。
g++ -I/usr/include/eigen3 main.cpp
In file included from /usr/include/c++/12.2.0/x86_64-pc-linux-gnu/bits/c++allocator.h:33,
from /usr/include/c++/12.2.0/bits/allocator.h:46,
from /usr/include/c++/12.2.0/string:41,
from /usr/include/c++/12.2.0/bits/locale_classes.h:40,
from /usr/include/c++/12.2.0/bits/ios_base.h:41,
from /usr/include/c++/12.2.0/ios:42,
from /usr/include/c++/12.2.0/istream:38,
from /usr/include/c++/12.2.0/sstream:38,
from /usr/include/c++/12.2.0/complex:45,
from /usr/include/eigen3/Eigen/Core:50,
from /usr/include/eigen3/Eigen/Dense:1,
from /usr/include/eigen3/Eigen/Eigen:1,
from main.cpp:1:
/usr/include/c++/12.2.0/bits/new_allocator.h: In instantiation of ‘void std::__new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Args = {Eigen::BiCGSTAB<Eigen::SparseMatrix<double, 0, int>, Eigen::DiagonalPreconditioner<double> >}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >]’:
/usr/include/c++/12.2.0/bits/alloc_traits.h:516:17: required from ‘static void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Args = {Eigen::BiCGSTAB<Eigen::SparseMatrix<double, 0, int>, Eigen::DiagonalPreconditioner<double> >}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; allocator_type = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >]’
/usr/include/c++/12.2.0/bits/vector.tcc:117:30: required from ‘std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {Eigen::BiCGSTAB<Eigen::SparseMatrix<double, 0, int>, Eigen::DiagonalPreconditioner<double> >}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; reference = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&]’
/usr/include/c++/12.2.0/bits/stl_vector.h:1294:21: required from ‘void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; value_type = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >]’
main.cpp:9:18: required from here
/usr/include/c++/12.2.0/bits/new_allocator.h:175:11: error: use of deleted function ‘Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >::BiCGSTAB(const Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&)’
175 | { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/eigen3/Eigen/IterativeLinearSolvers:42,
from /usr/include/eigen3/Eigen/Sparse:31,
from /usr/include/eigen3/Eigen/Eigen:2:
/usr/include/eigen3/Eigen/src/IterativeLinearSolvers/BiCGSTAB.h:158:7: note: ‘Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >::BiCGSTAB(const Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&)’ is implicitly deleted because the default definition would be ill-formed:
158 | class BiCGSTAB : public IterativeSolverBase<BiCGSTAB<_MatrixType,_Preconditioner> >
| ^~~~~~~~
/usr/include/eigen3/Eigen/src/IterativeLinearSolvers/BiCGSTAB.h:158:7: error: use of deleted function ‘Eigen::IterativeSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::IterativeSolverBase(const Eigen::IterativeSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >&)’
In file included from /usr/include/eigen3/Eigen/IterativeLinearSolvers:38:
/usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IterativeSolverBase.h:143:7: note: ‘Eigen::IterativeSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::IterativeSolverBase(const Eigen::IterativeSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >&)’ is implicitly deleted because the default definition would be ill-formed:
143 | class IterativeSolverBase : public SparseSolverBase<Derived>
| ^~~~~~~~~~~~~~~~~~~
/usr/include/eigen3/Eigen/src/IterativeLinearSolvers/IterativeSolverBase.h:143:7: error: use of deleted function ‘Eigen::SparseSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::SparseSolverBase(const Eigen::SparseSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >&)’
In file included from /usr/include/eigen3/Eigen/SparseCore:64,
from /usr/include/eigen3/Eigen/Sparse:26:
/usr/include/eigen3/Eigen/src/SparseCore/SparseSolverBase.h:67:7: note: ‘Eigen::SparseSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::SparseSolverBase(const Eigen::SparseSolverBase<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >&)’ is implicitly deleted because the default definition would be ill-formed:
67 | class SparseSolverBase : internal::noncopyable
| ^~~~~~~~~~~~~~~~
/usr/include/eigen3/Eigen/src/SparseCore/SparseSolverBase.h:67:7: error: ‘Eigen::internal::noncopyable::noncopyable(const Eigen::internal::noncopyable&)’ is private within this context
In file included from /usr/include/eigen3/Eigen/Core:162:
/usr/include/eigen3/Eigen/src/Core/util/Meta.h:424:21: note: declared private here
424 | EIGEN_DEVICE_FUNC noncopyable(const noncopyable&);
| ^~~~~~~~~~~
In file included from /usr/include/c++/12.2.0/vector:63,
from /usr/include/c++/12.2.0/functional:62,
from /usr/include/eigen3/Eigen/Core:85:
/usr/include/c++/12.2.0/bits/stl_uninitialized.h: In instantiation of ‘constexpr bool std::__check_constructible() [with _ValueType = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&&]’:
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:182:4: required from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = move_iterator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*>; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*]’
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:372:37: required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, allocator<_Tp>&) [with _InputIterator = move_iterator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*>; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >]’
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:397:2: required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _ForwardIterator = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >*; _Allocator = allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >]’
/usr/include/c++/12.2.0/bits/vector.tcc:487:3: required from ‘void std::vector<_Tp, _Alloc>::_M_realloc_insert(iterator, _Args&& ...) [with _Args = {Eigen::BiCGSTAB<Eigen::SparseMatrix<double, 0, int>, Eigen::DiagonalPreconditioner<double> >}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; iterator = std::vector<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >::iterator]’
/usr/include/c++/12.2.0/bits/vector.tcc:123:21: required from ‘std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {Eigen::BiCGSTAB<Eigen::SparseMatrix<double, 0, int>, Eigen::DiagonalPreconditioner<double> >}; _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; reference = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >&]’
/usr/include/c++/12.2.0/bits/stl_vector.h:1294:21: required from ‘void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >; _Alloc = std::allocator<Eigen::BiCGSTAB<Eigen::SparseMatrix<double> > >; value_type = Eigen::BiCGSTAB<Eigen::SparseMatrix<double> >]’
main.cpp:9:18: required from here
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:90:56: error: static assertion failed: result type must be constructible from input type
90 | static_assert(is_constructible<_ValueType, _Tp>::value,
| ^~~~~
/usr/include/c++/12.2.0/bits/stl_uninitialized.h:90:56: note: ‘std::integral_constant<bool, false>::value’ evaluates to false我使用的是eigen3.4和g++版本12.2。
有什么办法解决这个问题吗?
发布于 2022-12-04 13:20:46
把我的评论变成一个恰当的答案:
在查看了代码之后,我发现BiCGSTAB和所有的解决程序一样,是从一个基类继承的,这个基类旨在防止复制,并且通过扩展也可以防止移动:class SparseSolverBase : internal::noncopyable。
这个设计选择的确切原因我不知道。如果我不得不猜测,我会说一些求解者可能会使用自引用属性(持有指向其他成员的指针),这将特别是在固定大小的矩阵中中断。或者使用Eigen::Map可能会导致复制问题,特别是复制分配问题。
std::vector只适用于可移动类型,因为它需要在重新分配时移动。即使事先调用reserve(),代码仍然需要编译,即使它从未被执行。
我想到了三个解决办法:
std::deque。它提供了向量拥有的所有方法的超集,但是它的实现意味着只要您只调用emplace_back或emplace_front,而不调用insert,它就不需要可移动的类型。缺点是,在所有单独访问的过程中,速度都要慢一点。
std::vector<std::unique_ptr<Solver>>。效率不如deque,但现在您还可以插入、重新洗牌等。
std::unique_ptr<Solver[]>并使用好的旧new Solver[count]分配。从C++14开始,您可以使用std::make_unique<Solver[]>(count)。这具有最少的开销,甚至小于向量,但是接口不太好(您可以使用[index]运算符,但指针甚至不知道数组大小),在分配之后,这个数字是固定的。
https://stackoverflow.com/questions/74672400
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