```
void add(sparseMatrix<T> &b, sparseMatrix<T> &c); // c is output
sparseMatrix<T> operator+(sparseMatrix<T> &b);
```

I'm creating a sparse matrix which is made up of an arrayList of singly linked lists of matrix terms (matrix terms contain the row, column, and value). I'm having trouble overloading the + operator. I have an add method which works fine, but when I try to use it to overload the + operator I get the following errors:

```
sparseMatrix.cpp: In function ‘int main()’:
sparseMatrix.cpp:268: error: no match for ‘operator=’ in ‘c = sparseMatrix<T>::operator+(sparseMatrix<T>&) [with T = int](((sparseMatrix<int>&)(& b)))’
sparseMatrix.cpp:174: note: candidates are: sparseMatrix<T>& sparseMatrix<T>::operator=(sparseMatrix<T>&) [with T = int]
make: *** [sparseMatrix] Error 1
```

Here is my implementation for the overloaded + operator:

```
sparseMatrix<T> sparseMatrix<T>::operator+(sparseMatrix<T> &b)
{
sparseMatrix<T> c;
add(b, c);
return c;
}
```

The line in main that gives the error is c = a + b (a, b, c are all sparse matrices). Note that if I do a.add(b,c) everything works fine. I have also overloaded the = operator which works when I do a = b etc. but it seems to be complaining about it in the error message I posted. I'm really not sure what the problem is. Any ideas?

note: candidates are: sparseMatrix& sparseMatrix::operator=(sparseMatrix&)

Your `operator=`

should take a **const** reference.

If the reference isn't const, it can't be bound to a temporary, so the assignment operator can't be used for the temporary created by `a + b`

.

(The same is true for `operator+`

, here also the argument should be `const sparseMatrix<T> &`

. Additionally this method should be declared as const, since it doesn't modify the object it is called on.)

sth: has correctly diagnosed the problem:

But I would make your operators more standard.

```
class sparseMatrix
{
sparseMatrix(sparseMatrix const& copy);
sparseMatrix& operator=(sparseMatrix const& copy);
sparseMatrix& add(sparseMatrix const& value) // Add value to the current matrix
{
// Do Work.
return *this;
}
// Re-use add to implement the += operator.
sparseMatrix& operator+=(sparseMatrix const& rhs)
{
return add(rhs);
}
// Two things here:
//
// Implement the operator + in terms of the operator +=
//
// This basically means that you make a copy of one parameter then add the other
// value two it. Because + is symmetric it does not matter which you copy and which
// you add to the copy.
//
// So we pass the parameter by value this will provide an implicit copy
// generated by the compiler. This will also help the compiler with NRVO
// Then we just add (*this) to the copy of the rhs.
sparseMatrix operator+(sparseMatrix rhs)
{
return rhs += *this;
}
}
```

Similar Questions

The code for my question can be located at http://matthewh.me/Scripts/c++/graphs/. The user name is guest password is guest. This will give you read access to the svn repository. I do this to save you

In the class Matrix typedef std::vector < std::vector <double> > TItems; class Matrix { private : TItems items; public: double & operator() ( int r, int c ) {return items[r][c];} Matri

I work on converting a large Matlab code to C++ and CUDA. I have problems converting some sparse matrix operations like: 1. full_Matrix * sparse_Matrix 2. sparse_Matrix * full_Matrix 3. sparse_Matrix

I'm learning C++ and we've been assigned the task of implementing Vector3D classes using Stack and Heap memory. By accident, I've noticed that it is possible to access the protected member fields x, y

How can i overload operator[] to make it return b[i] but as a part of object ob2 of class C? I tried to do it as a friend methot but it didnt worked. (The main task is to correct the code without chan

When overloading operators, is it necessary to overload >= <= and !=? It seems like it would be smart for c++ to call !operator= for !=, !> for operator<= and !< for operator>=. Is t

How can you add a 1-column matrix to a sparse matrix, or add a sparse matix to a column matrix (either way)? It shouldn't replace the data, just join it into one data type. The sparse matrix: >>

class sock { public: SOCKET m_hSock; ..... //Other functons...contructors, destructors ..... operator SOCKET() { return m_hSock;} } In above coscket class code, what operator it is overloading?

In c++ you can create new instances of a class on both the heap and stack. When overloading an operator are you able to instantiate on the stack in a way that makes sense? As I understood it an instan

please take your time viewing the code below and answer my queries regarding it class Vector { public: int x, y; /* Constructor / destructor / Other methods */ Vector operator + (Vector & OtherVec

What scenarios would you consider operator overloading in .net?

I'm trying to transpose a sparse matrix in c++. I'm struggling with the traversal of the new transposed matrix. I want to enter everything from the first row of the matrix to the first column of the n

public static ListOfPeople operator +( ListOfPeople x, Person y) { ListOfPeople temp = new ListOfPeople(x); if(!temp.PeopleList.Contains(y)) { temp.PeopleList.Add(y); } temp.SaveNeeded = true; return

I'm writing a program that take vectors and modify them but it gives me Error: variable 'Vector' is not a type name I'm new to c++ overloaded operators so their might be a lot of syntax error wha

I was going through some of the theory of assignment operator of c++. Let's say class MyClass { private: T1 member1; T2 member2; public: // The default copy assignment operator which assigns an object

I need to overload the stream extraction operator. I need to do this by allowing a user to input a string of characters at a prompt, say iamastring, and then the operator would extract each characte

I am using a sparse matrix format implemented in scipy as csr_matrix. I have a mat variable which is in csr_matrix format and all its elements are non-negative. However, when I use mat + mat operation

A homework assignment calls for the overloading of the consignment operator for a Heap class that is used to store pointers to queues at every node in an attempt to emulate a Emergency room priority q

I've got some problems whith the overload of operator=. My code is #include <stdlib.h> #include <iostream> const std::size_t DIM = 10; template <typename T> class rowvec { private: T

Here are an example of operator overloading from C++ programming language: struct X{ int I; X(int); X operator+(int); }; struct Y{ int I; Y(X); Y operator+(X); operator int(); } I am not clear about

I am using Python with numpy, scipy and scikit-learn module. I'd like to classify the arrays in very big sparse matrix. (100,000 * 100,000) The values in the matrix are equal to 0 or 1. The only thing

I'm puzzled with this behavior of C++: struct A { virtual void print() const { printf(a\n); } }; struct B : public A { virtual void print() const { printf(b\n); } }; struct C { operator B() { retu

I'm just a beginner in the C++ language and I have some questions on this piece of code. I am trying to overload some operators. string& operator = (char R) { string T = R ; *this = T; return *thi

if I overloading the + operator, I can use this(assume the class is className) className operator+(className & c) { // version 1 className T; ... return T; } also I can use className operator+(c

I am trying to learn operator overloading by working on overloading >> for a matrix class to enable the key-board based input for a matrix by calling sth such as Matrix M1; cin >> M1; Th

Does anyone have a summary of boilerplate declarations for C++ operator overloading? A one page pdf would be nice. It would help us forgetful people having to stop and think about where to put our con

I am trying to overload the * operator in order to multiply two objects (dot product). These objects can be Point3D, Vector3D or Normal. They all basically have the same structure (an x, y, and z valu

I have this declaration struct Z { void operator ()( int a ) { cout << operator()() << a << endl; } }; Z oz, *zp = &oz; oz(1); //ok (*zp)(2); //ok zp(3); //error: 'zp' cannot

Are there any algorithms that allow efficient creation (element filling) of sparse (e.g. CSR or coordinate) matrix in parallel?

I need to overload = operator in my class SparseMatrix. template <class T> class SparseMatrix { public: template <class T> class element { public: int x; int y; T val; element(T war, int x

Is there some easy and fast way to convert a sparse matrix to a dense matrix of doubles? Because my SparseMatrix is not sparse any more, but became dense after some matrix products. Another question I

I was trying to use the overload operator method to copy the entries of one queue into another, but I am going wrong with my function. I don't know how else to access the values of the queue original

I have first encounter operator overloading in .Net, long back I had used it in C++, but that was like overloading operators like +, now I have suddenly scenario as below. I have a struct AccessToke

Ok, I am working through a book and trying to learn C++ operator overloading. I created a BigInt class that takes a single int (initially set to 0) for the constructor. I overloaded the += method and

here is the code for my question: class ICommon { public: virtual ICommon& operator=(const ICommon & p)const=0; }; class CSpecial : public ICommon { public: CSpecial& operator=(const CSp

I have a question about Eigen library in C++. Actually, I want to calculate inverse matrix of sparse matrix. When I used Dense matrix in Eigen, I can use .inverse() operation to calculate inverse of d

Possible Duplicate: Operator Overloading in C++ as int + obj I override the * operator as following: Point Point::operator *(float scale){ Point point(this->x*scale, this->y*scale); return poi

I am busy doing an assignment for a Comp Sci module in C++ and I am just a bit confused by one of the questions. It asks to give 3 implementations of an overloaded increment operator: Using the membe

I am currently starting to look into operator overloading in c++ for a simple 2D vertex class where the position should be available with the [] operator. That generally works, but I dont really know

I'm looking for a matrix / linear algebra library in Java that provides a sparse matrix that can be written to concurrently from different threads. Most of the libraries I've come across either do not

I have to make for a project an Album class which uses a Song class. I seem to have problem with overloading the << operator for the Album class. So this is the album class const int Empty=-1 cl

I'm thinking of using Boost's Sparse Matrix for a computation where minimal memory usage is the goal. Unfortunately, the documentation page didn't include a discussion of the sparse matrix implementat

I have a matrix of factors in R and want to convert it to a matrix of dummy variables 0-1 for all possible levels of each factors. However this dummy matrix is very large (91690x16593) and very spar

I've a Sparse matrix in CSR Sparse format in python and I want to import it to MATLAB. MATLAB does not have a CSR Sparse format. It has only 1 Sparse format for all kind of matrices. Since the matrix

I am writing a java program which involves working with a 1058 X 1058 matrix containing float values. This matrix contains many zero values and so I need to store this as a sparse matrix and later use

I have a conversion like this: Class1 *p1; Class2 *p2 = new Class2(); p1 = (Class1 *) p2; Can I override the typecast operator above to return a custom Class1 object pointer? If yes how? EDIT: My exa

Possible Duplicate: Can I overload an operator in Objective-C? In, objective-C++, is it possible to overload the message passing operator, i.e. the []? Is it possible to the same with .?

I'm basically trying to do the example of StratifiedShuffleSplit but with X not being an array but a sparse matrix. In the example below, this matrix was created by a DictVectorizer fit to an array of

In the following codes, I illustrate an example of operator overloading: #include <iostream> using namespace std; template <typename T> class A { public: A() {}; A( T &obj) {value = ob

I'm trying to understand the purpose of overloading some operators in C++. Conceptually, an assignment statement can be easily implemented via: Destruction of the old object followed by copy construc