std::ios_base::~ios_base
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                    |   virtual ~ios_base();  | 
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Destroys the ios_base object. 
Before any of the member functions would yield undefined results, calls callbacks, registered by register_callback() passing erase_event as parameter. Then, deallocates any memory obtained.
No operations on rdbuf are performed, it is not destroyed.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior | 
|---|---|---|---|
| LWG 3434 | C++98 |  the destructor was not required to reclaim memory for iarray and parray
 | 
required |