57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
#include <iostream>
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#include <vector>
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#include <cstring>
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class LargeObject {
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public:
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// constructor allocating a large amount of memory
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LargeObject(int size) {
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size_ = size;
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data_ = new char[size_];
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// initialize data with some values
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std::memset(data_, 'A', size_);
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}
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// copy constructor
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LargeObject(const LargeObject& other) {
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size_ = other.size_;
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data_ = new char[size_];
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std::memcpy(data_, other.data_, size_);
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}
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// move constructor
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// marking functions as noexcept allows the compiler to make certain optimizations,
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// knowing that the function won't emit exceptions. This can result in more efficient code generation.
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LargeObject(LargeObject&& other) noexcept {
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size_ = other.size_;
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data_ = other.data_;
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other.data_ = nullptr;
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other.size_ = 0;
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}
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// destructor
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~LargeObject() {
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delete[] data_;
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}
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private:
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size_t size_;
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char* data_;
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};
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int main() {
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int numElements = 1000000; // number of elements
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int dataSize = 1024; // size of each LargeObject's data
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std::vector<LargeObject> vec;
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for (size_t i = 0; i < numElements; ++i) {
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vec.emplace_back(dataSize); // move constructor would get called here
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// when a std::vector exceeds its current capacity,
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// it allocates a larger block of memory and moves existing elements to the new storage location.
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// This reallocation process involves calling the move constructor for each existing element.
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}
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return 0;
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}
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