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std::get_temporary_buffer

From cppreference.com
< cpp‎ | memory
 
 
 
 
Defined in header <memory>
template< class T >
std::pair< T*, std::ptrdiff_t > get_temporary_buffer( std::ptrdiff_t count );

Allocates storage sufficient to store up to count adjacent objects of type T. If there is insufficient memory for all count objects, allocates less than count, if possible.

Contents

[edit] Parameters

count - the number of objects to allocate

[edit] Return value

An std::pair holding a pointer to the beginning of the allocated storage and the number of objects that fit in the storage that was actually allocated (may be zero).

[edit] Exceptions

(none) (until C++11)
noexcept specification:  
noexcept
  
(since C++11)

[edit] Example

#include <algorithm>
#include <iostream>
#include <memory>
#include <string>
#include <iterator>
 
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)
 
    std::copy(s, s + p.second,
              std::raw_storage_iterator<std::string*, std::string>(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>();
    });
 
    std::return_temporary_buffer(p.first);
}

Output:

string
1
test
...

[edit] See also

frees uninitialized storage
(function template) [edit]