Questions tagged [copy-assignment]
146 questions
0
votes
1 answer
Why isn't the copy assingnment operator called when the copy construcotr is not available in C++?
Why when let's say I have an object declared like this: Obj o1; which is initialized by the default constructor (not very important here, how was o1 initialized, the point is it was initialized) and I create another object in this manner: Obj o2 =…
pauk
- 350
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- 15
0
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0 answers
copy sematics for callable objects involving "this" pointer
I have a class member which is of type std::function that binds to this pointer by using std::bind.
I implemented assignment operator which must also copy the callable object, however issue is in that, which this should be copied? this this or other…
metablaster
- 1,958
- 12
- 26
0
votes
1 answer
Value assignment isn't working as expected
The assignment isn't working as I want. I'm trying to get the convergence of my calculations, so I'm iterating the function through the for loop, and I want break the loop when I get the tolerance. The function gives me an array D[nr, nz], I iterate…
Marcelo
- 77
- 9
0
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1 answer
constructing a std::function object from a type with a variadic template constructor
I have a templated class which instantiates an internal object of the template type and its constructor forwards the arguments to the internal object.
template
struct B
{
template
B(Args&&... args) :…
Zamfir Yonchev
- 151
- 1
- 10
0
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0 answers
Copy And Assignment: How to Deep Copy? C++
I have two classes that are essentially string classes that look like this.
The first class holds a string as a member and the second class also holds a string plus an array of pointers for the 'MenuItem' class and also a tracker.
const int…
AKidNamedCoder
- 3
- 3
0
votes
1 answer
The difference between initialize a object and assign to an object
I'm working on some basic object practice and I faced this problem.
This class is named Matrix, and I tried to initialize a7 to a2.mutiply(a5).
But the result is quite different when I tried to intialize a7 at first,
and assign it to a2.mutiply(a5)…
niorix
- 65
- 6
0
votes
0 answers
Proper way to implement copy-assignment operator
I am trying to understand the correct way to implement the copy-assignment operator =. So I've implemented this example:
class Window {
public:
Window(const std::string& = std::string());
Window(const Window&);
Window& operator=(const…
Itachi Uchiwa
- 3,044
- 12
- 26
0
votes
0 answers
Copy Assignment constructor in c++
I get this error while trying to create a copy assignment constructor: "overloaded operator must be a binary operator"
this is my code:
header:
class User{
public:
User(const std::string& name);
const User& operator=(const User &other);
…
Maya Saias
- 37
- 9
0
votes
0 answers
C++ assignment by value, what are the drawbacks?
Recently, I have stumbled over this pattern:
class Foo {
Foo() = default;
Foo(const Foo &) = default;
Foo(Foo &&) = default;
Foo & operator=(Foo rhs) {
swap(rhs);
return *this;
}
};
A close look at this pattern revealed…
user666412
- 528
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- 18
0
votes
2 answers
Assigment Operator for objects with user defined pointer members
I am trying to implement an operator= in C++ for an object which has as a member a pointer to a user defined type which also has dynamic memory allocated in it.
So given the code below, how would on implement a correct operator= for B? What I am…
I Radu
- 11
- 2
0
votes
0 answers
Copy assignment not chosen
Given the following code snippet, why isn't the copy assignment operator chosen?
It doesn't compile complaining about the copy constructor being deleted. I tried with a user declared assignment operator, but it still didn't work. So it isn't an…
scx
- 3,221
- 1
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- 37
0
votes
2 answers
recursive call in copy constructor
I implemented a class following the rule of three, and I am getting a crash. Upon debugging I have came to the conclusion that the copy constructor is calling itself repeatedly instead of calling the equality operator. Why is this so? Shouldn't it…
Daniyal Yasin
- 142
- 1
- 14
0
votes
1 answer
Why Implementation for is_copy_assignable doesn't work?
This is my attempt at an implementation for is_copy_assignable:
template
struct IsCopyAssignable : std::false_type
{};
template
struct IsCopyAssignable::type =…
KeyC0de
- 4,728
- 8
- 44
- 68
0
votes
1 answer
Doesn't work Copy Assignment Operator
In my code, I am having trouble on my copy assignment operator. When I try to execute "=" operator in my main(), the content of my source array (numArr) is not copied to my destenation array (numArr2).
Then, for my doubleCap() function, I am try to…
Coded-Blood Junior
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0
votes
3 answers
Is it safe to copy a class into uninitialized memory?
I have to use malloc to allocate memory. I have a custom class that needs a custom operator=. Let's say it is A:
class A {
public:
int n;
A(int n) : n(n) {}
A& operator=(const A& other) {
n = other.n;
return *this;
}
};
I allocate…
Pedro Palacios
- 153
- 9