std::return_temporary_buffer
Min standard notice:
Header: <memory>
Deallocates the storage referenced by p.
# Declarations
template< class T >
void return_temporary_buffer( T* p );
(deprecated in C++17) (removed in C++20)
# Parameters
p: the pointer referring to the storage to be declloated
# Return value
(none)
# Example
#include <algorithm>
#include <iostream>
#include <iterator>
#include <memory>
#include <string>
int main()
{
const std::string s[] = {"string", "1", "test", "..."};
const auto p = std::get_temporary_buffer<std::string>(4);
// requires that p.first is passed to return_temporary_buffer
// (beware of early exit points and exceptions), or better use:
std::unique_ptr<std::string, void(*)(std::string*)> on_exit(p.first,
[](std::string* p)
{
std::cout << "returning temporary buffer...\n";
std::return_temporary_buffer(p);
});
std::copy(s, s + p.second,
std::raw_storage_iterator<std::string*, std::string>(p.first));
// has same effect as: std::uninitialized_copy(s, s + p.second, p.first);
// requires that each string in p is individually destroyed
// (beware of early exit points and exceptions)
std::copy(p.first, p.first + p.second,
std::ostream_iterator<std::string>{std::cout, "\n"});
std::for_each(p.first, p.first + p.second, [](std::string& e)
{
e.~basic_string<char>();
}); // same as: std::destroy(p.first, p.first + p.second);
// manually reclaim memory if unique_ptr-like technique is not used:
// std::return_temporary_buffer(p.first);
}
# Defect reports
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2072 | C++98 | the storage allocated by std::get_temporary_buffercould be deallocated multiple times | the behavior isundefined in this case |