CODEWITHSUNDEEP
c++copyoperator-overloadingmove-semanticsrvalue
Hrant Nurijanyan
Hrant Nurijanyan

Reputation: 929

Operator overloading, Rvalues, C++

Consider a struct

template<typename T, size_t N>
struct Something {
    std::array<T,N> args;

    // Some constructors

};

Now let's overload = operator for Something<T>. In fact I can implement it two ways.

First Way

Something& operator=(const Something& rhs){
    // an implementation with copy semantics
}

Something& operator=(Something&& rhs) {
    // an implementation with move semantics
}

Second Way

Something& operator=(Something rhs){
    // implement with move semantics
}

So, my question is what is the most standard way and the most optimal way to do overloading First Way or Second Way?

Upvotes: 0

Views: 108

Answers (1)

463035818_is_not_an_ai
463035818_is_not_an_ai

Reputation: 122133

For this particular case you should not implement the assignment operator. The compiler does that already for you:

#include <array>
#include <cstddef>

template<typename T, size_t N>
struct Something {
    std::array<T,N> args;
};

int main() {
    Something<int,42> a;
    Something<int,42> b;
    a = b;
}

Demo

For the general case I refer you to What are the basic rules and idioms for operator overloading?. And consider that not everything can be moved and not everything can be copied. Moreover, sometimes a move is just a copy. Hence, it depends.

Upvotes: 2

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