我的第一个模板类尝试从一些boost compressed_matrix到PETSc Sparse AIJ格式的简化转换器,但我在一开始就遇到迭代器typedef declerations的问题。所以T是compressed_matrix,天真地使用下面的代码会导致编译时错误,应该如何定义这些迭代器。我应该多阅读一下这个模板......
template <class T, class T1>
int converter<T, T1>::convertMBo2Pe( const T& A,
T1 A_ ){
PetscErrorCode ierr;
int cntNnz = 0;
typedef T::iterator1 i1_t;
typedef T::iterator2 i2_t;
//int nnz[ooFelieMatrix.size1()];
int nnz[A.size1()];
unsigned ind=0;
//get information about the matrix
double* vals = NULL;
for (i1_t i1 = A.begin1(); i1 != A.end1(); ++i1)
{
nnz[ind] = distance(i1.begin(), i1.end());
ind++;
}
// create the matrix depending
// on the values of the nonzeros
// on each row
ierr = MatCreateSeqAIJ( PETSC_COMM_SELF, A.size1(),
A.size2(), cntNnz, nnz,
A_ );
PetscInt rInd = 0, cInd=0;
PetscInt* rCount, dummy;
rCount = &dummy;
// pointer to values in a row
PetscScalar* valsOfRowI = NULL;
PetscInt* colIndexOfRowI = NULL;
PetscInt rC = 1;
for(i1_t i1 = A.begin1(); i1 != A.end1(); ++i1)
{
// allocate space for the values of row I
valsOfRowI = new PetscScalar[nnz[rInd]];
colIndexOfRowI = new PetscInt[nnz[rInd]];
for(i2_t i2 = i1.begin(); i2 != i1.end(); ++i2)
{
colIndexOfRowI[cInd] = i2.index2();
valsOfRowI[cInd] = *i2;
cInd++;
}
// setting one row each time
*rCount = rInd;
MatSetValues( A_, rC, rCount, nnz[rInd],
colIndexOfRowI, valsOfRowI,
INSERT_VALUES );
// delete
delete [] valsOfRowI;
delete [] colIndexOfRowI;
rInd++; cInd = 0;
}
//
MatAssemblyBegin( A_, MAT_FINAL_ASSEMBLY );
MatAssemblyEnd( A_, MAT_FINAL_ASSEMBLY );
// return
return 0;
}
答案 0 :(得分:1)
您必须明确告诉编译器T::iterator1
是一个类型名称(与静态变量相反,或者沿着这些行)。
typedef typename T::iterator1 i1_t;