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Modern C++ · medium

2. Move Semantics & Rvalue References (std::move)

Eliminating deep copies with resource theft.

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Move semantics (introduced in C++11) transfer ownership of heap resources from temporary rvalues (`&&`) to new objects without allocating or copying memory buffers.

cpp
std::vector<int> a = {1, 2, 3};
std::vector<int> b = std::move(a); // a's internal pointer stolen by b

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Check your understanding

1. What does std::move actually do at runtime?
Casts an lvalue to an rvalue reference (&&) enabling move constructionCopies data in the backgroundDeletes the objectLocks a thread
2. What state is an object left in after being moved from?
Valid but unspecified stateDeleted from memoryNull pointerCompiles to 0

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