From cppreference.com
template<classT>voidreturn_temporary_buffer(T*p);(deprecated in C++17)
(removed in C++20)Deallocates the storage referenced by p.
If p is not a pointer value returned by an earlier call to
, or has been invalidated by an intervening std::return_temporary_buffer call, the behavior is undefined.
Parameters
p - the pointer referring to the storage to be declloated Return value
(none)
Exceptions
Throws nothing.
Example
Run this code
#include<algorithm>#include<iostream>#include<iterator>#include<memory>#include<string>intmain(){conststd::strings[]={"string","1","test","..."};constautop=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);}Output:
string 1 test ... returning temporary buffer... Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior
C++98 the storage allocated by
could be deallocated multiple times the behavior is
undefined in this case See also