Difference between revisions of "cpp/memory/new/bad alloc"
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class bad_alloc; | class bad_alloc; | ||
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===Member functions=== | ===Member functions=== | ||
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===Example=== | ===Example=== | ||
{{example | {{example | ||
| − | + | |code= | |
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#include <iostream> | #include <iostream> | ||
#include <new> | #include <new> | ||
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int main() | int main() | ||
{ | { | ||
| − | try { | + | try |
| − | while (true) { | + | { |
| + | while (true) | ||
| + | { | ||
new int[100000000ul]; | new int[100000000ul]; | ||
} | } | ||
| − | } catch (const std::bad_alloc& e) { | + | } |
| + | catch (const std::bad_alloc& e) | ||
| + | { | ||
std::cout << "Allocation failed: " << e.what() << '\n'; | std::cout << "Allocation failed: " << e.what() << '\n'; | ||
} | } | ||
} | } | ||
| − | + | |p=true | |
| − | + | |output= | |
Allocation failed: std::bad_alloc | Allocation failed: std::bad_alloc | ||
}} | }} | ||
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===See also=== | ===See also=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/memory/new/dsc operator_new}} | + | {{dsc inc|cpp/memory/new/dsc operator_new}} |
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Latest revision as of 09:07, 14 June 2023
| Defined in header <new>
|
||
| class bad_alloc; |
||
std::bad_alloc is the type of the object thrown as exceptions by the allocation functions to report failure to allocate storage.
Inheritance diagram
Contents |
[edit] Member functions
| (constructor) |
constructs a new bad_alloc object (public member function) |
| operator= |
replaces the bad_alloc object (public member function) |
| what |
returns the explanatory string (public member function) |
std::bad_alloc::bad_alloc
| (1) | ||
bad_alloc() throw(); |
(until C++11) | |
| bad_alloc() noexcept; |
(since C++11) | |
| (2) | ||
bad_alloc( const bad_alloc& other ) throw(); |
(until C++11) | |
| bad_alloc( const bad_alloc& other ) noexcept; |
(since C++11) | |
Constructs a new bad_alloc object with an implementation-defined null-terminated byte string which is accessible through what().
1) Default constructor.
2) Copy constructor. If *this and other both have dynamic type
std::bad_alloc then std::strcmp(what(), other.what()) == 0.(since C++11)Parameters
| other | - | another exception object to copy |
std::bad_alloc::operator=
bad_alloc& operator=( const bad_alloc& other ) throw(); |
(until C++11) | |
| bad_alloc& operator=( const bad_alloc& other ) noexcept; |
(since C++11) | |
Assigns the contents with those of other. If *this and other both have dynamic type std::bad_alloc then std::strcmp(what(), other.what()) == 0 after assignment.(since C++11)
Parameters
| other | - | another exception object to assign with |
Return value
*this
std::bad_alloc::what
virtual const char* what() const throw(); |
(until C++11) | |
| virtual const char* what() const noexcept; |
(since C++11) | |
Returns the explanatory string.
Parameters
(none)
Return value
Pointer to a null-terminated string with explanatory information. The string is suitable for conversion and display as a std::wstring. The pointer is guaranteed to be valid at least until the exception object from which it is obtained is destroyed, or until a non-const member function (e.g. copy assignment operator) on the exception object is called.
Notes
Implementations are allowed but not required to override what().
Inherited from std::exception
Member functions
| [virtual] |
destroys the exception object (virtual public member function of std::exception)
|
| [virtual] |
returns an explanatory string (virtual public member function of std::exception)
|
[edit] Example
Run this code
#include <iostream> #include <new> int main() { try { while (true) { new int[100000000ul]; } } catch (const std::bad_alloc& e) { std::cout << "Allocation failed: " << e.what() << '\n'; } }
Possible output:
Allocation failed: std::bad_alloc
[edit] See also
| allocation functions (function) |
