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C++ Move Semantics

bookRvalue References Overview

Rvalue references, introduced in C++11, use the syntax T&&. They allow functions to distinguish between lvalues and rvalues, enabling move semantics.

main.cpp

main.cpp

copy

              
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#include <iostream>

void process(int& x)
{
    std::cout << "Lvalue reference called with " << x << std::endl;
}

void process(int&& x)
{
    std::cout << "Rvalue reference called with " << x << std::endl;
}

int main()
{
    int a = 42;
    process(a);      // lvalue, calls process(int&)
    process(99);     // rvalue, calls process(int&&)
    process(std::move(a)); // rvalue, calls process(int&&)
}

Notice in the example above how the function overloads are selected based on whether the argument is an lvalue or an rvalue. This distinction is the foundation for move semantics.

question mark

Which statements about rvalue references and move semantics are correct

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 3

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bookRvalue References Overview

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Rvalue references, introduced in C++11, use the syntax T&&. They allow functions to distinguish between lvalues and rvalues, enabling move semantics.

main.cpp

main.cpp

copy

              
12345678910111213141516171819

            
#include <iostream>

void process(int& x)
{
    std::cout << "Lvalue reference called with " << x << std::endl;
}

void process(int&& x)
{
    std::cout << "Rvalue reference called with " << x << std::endl;
}

int main()
{
    int a = 42;
    process(a);      // lvalue, calls process(int&)
    process(99);     // rvalue, calls process(int&&)
    process(std::move(a)); // rvalue, calls process(int&&)
}

Notice in the example above how the function overloads are selected based on whether the argument is an lvalue or an rvalue. This distinction is the foundation for move semantics.

question mark

Which statements about rvalue references and move semantics are correct

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 3
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