In this article, you will learn about the std::gettemporarybuffer in C++ with its syntax and examples.
What is the std::get_temporary_buffer?
The <memory> header in C++ contains the std::gettemporarybuffer function, which is used to get a temporary buffer to hold uninitialized memory for a specific number of objects. When the temporary buffer is no longer required, this function is usually used in conjunction with the std::returntemporarybuffer function to release it.
Syntax:
It has the following syntax:
template <class T>
pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
Parameters:
n: The number of objects for which memory needs to be allocated.
Return Value:
std::pair<T*, ptrdiff_t>: It returns a pair containing a pointer to the beginning of the allocated memory block and the actual number of objects that can be stored in the allocated memory.
Exceptions:
It shouldn't raise any exceptions because the function is marked as noexcept . Nevertheless, some cases may still be exceptions because the implementation defines the behaviour.
Example 1:
Let's take an example to illustrate the use of the std::gettemporarybuffer in C++.
#include <memory>
#include <iostream>
int main() {
ptrdiff_t n = 5;
std::pair<int*, ptrdiff_t> buffer = std::get_temporary_buffer<int>(n);
if (buffer.second > 0) {
std::cout << "Successfully obtained a temporary buffer for " << buffer.second << " objects." << std::endl;
std::return_temporary_buffer(buffer.first);
} else {
std::cerr << "Failed to obtain a temporary buffer." << std::endl;
}
return 0;
}
Output:
Important Points:
- The <memory> header in C++ contains the std::gettemporarybuffer function, which is used to get a temporary buffer to hold uninitialized memory for a specific number of objects. When the temporary buffer is no longer required, this function is usually used in conjunction with the std::returntemporarybuffer function to release it.
- It shouldn't raise any exceptions because the function is marked as noexcept. Nevertheless, some cases may still be exceptions because the implementation defines the behaviour.
Remember that using std::gettemporarybuffer is comparatively low-level, and in contemporary C++, using higher-level abstractions like std::vector or smarcpp tutorialers ( std::uniqueptr or std::sharedptr ) is frequently advised to manage dynamic memory more conveniently and safely.
Benefits of std::get_temporary_buffer in C++:
The C++ Standard Library offers a function called std::gettemporarybuffer that lets you get a temporary buffer for dynamic memory allocation. This function is defined in the <memory_resource> header as of C++17 and is a <memory> header component.
The following are some advantages and applications for std::gettemporarybuffer:
- Effective Memory Allocation: std::get temporary buffer is primarily used to allocate a temporary buffer efficiently for a given number of objects. It can be especially helpful when you require temporary storage for a computation or operation.
- Resources for Custom Memory: Std::gettemporarybuffer can use custom memory resources as of C++17. This implies that by providing a custom allocator, you can use it with your memory management plan.
- Preventing Memory Fragmentation: Utilizing a temporary buffer can prevent memory fragmentation in situations where many small allocations and deallocations are performed. It enables you to allocate a single, large block of memory, which has the potential to be more effective than several smaller allocations.
- Exception Safety: A robust exception safety guarantee is built into the function. The function ensures that no resources are spilled and that the program stays in a consistent state if an exception is raised during allocation.
- Optimized for Performance: Std::gettemporarybuffer may employ unique memory allocation techniques.