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C++: Difference between revisions
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# Using free | # Using free | ||
std::unique_ptr<void *, decltype(std::free) *> my_buffer(std::malloc(10), std::free); | std::unique_ptr<void *, decltype(std::free) *> my_buffer(std::malloc(10), std::free); | ||
</syntaxhighlight> | |||
====Deallocate==== | |||
Normally, containers such as <code>std::vector</code> will automatically deallocate memory from the heap when the destructor is called. However, occationally you may want to coarse this deallocation yourself.<br> | |||
There are a few ways to do this: | |||
* Use smart pointers | |||
* Copy-and-swap idiom | |||
* Call a clear/shrink/deallocate function | |||
Example [https://stackoverflow.com/questions/3054567/right-way-to-deallocate-an-stdvector-object Reference]: | |||
<syntaxhighlight> | |||
// Using smart pointers | |||
std::unique_ptr<std::vector<float>> my_vector = make_unique<std::vector<float>>(99); | |||
my_vector->reset(); | |||
// Copy-and-swap idiom | |||
std::vector<float> my_vector(99); | |||
std::vector<int>().swap(my_vector); | |||
// Clear and shrink | |||
// Specific to std::vector | |||
std::vector<float> my_vector(99); | |||
my_vector.clear(); | |||
my_vector.shrink_to_fit(); | |||
</syntaxhighlight> | </syntaxhighlight> | ||