std:: bad_array_new_length

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Low level memory management
Defined in header <new>
class bad_array_new_length ;
(since C++11)

std::bad_array_new_length is the type of the object thrown as exceptions by the new-expressions to report invalid array lengths if

  1. Array length is negative,
  2. Total size of the new array would exceed implementation-defined maximum value,
  3. The number of initializer-clauses exceeds the number of elements to initialize.

Only the first array dimension may generate this exception; dimensions other than the first are constant expressions and are checked at compile time.

cpp/error/exception cpp/memory/new/bad alloc std-bad array new length-inheritance.svg

Inheritance diagram

Member functions

(constructor)
constructs a new bad_array_new_length object
(public member function)
operator=
replaces the bad_array_new_length object
(public member function)
what
returns the explanatory string
(public member function)

std::bad_array_new_length:: bad_array_new_length

bad_array_new_length ( ) noexcept ;
(1) (since C++11)
bad_array_new_length ( const bad_array_new_length & other ) noexcept ;
(2) (since C++11)

Constructs a new bad_array_new_length 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_array_new_length then std:: strcmp ( what ( ) , other. what ( ) ) == 0 .

Parameters

other - another exception object to copy

std::bad_array_new_length:: operator=

bad_array_new_length & operator = ( const bad_array_new_length & other ) noexcept ;
(since C++11)

Assigns the contents with those of other . If * this and other both have dynamic type std::bad_array_new_length then std:: strcmp ( what ( ) , other. what ( ) ) == 0 after assignment.

Parameters

other - another exception object to assign with

Return value

* this

std::bad_array_new_length:: what

virtual const char * what ( ) const noexcept ;
(since C++11)
(constexpr since C++26)

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.

The returned string is encoded with the ordinary literal encoding during constant evaluation.

(since C++26)

Notes

Implementations are allowed but not required to override what() .

Inherited from std:: bad_alloc

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 )

Notes

Feature-test macro Value Std Feature
__cpp_lib_constexpr_exceptions 202411L (C++26) constexpr for exception types

Example

Three conditions where std::bad_array_new_length should be thrown:

Run this code 
#include <climits>
#include <iostream>
#include <new>
 
int main()
{
    try
    {
        int negative = -1;
        new int[negative];
    }
    catch (const std::bad_array_new_length& e)
    {
        std::cout << "1) " << e.what() << ": negative size\n";
    }
 
    try
    {
        int small = 1;
        new int[small]{1,2,3};
    }
    catch (const std::bad_array_new_length& e)
    {
        std::cout << "2) " << e.what() << ": too many initializers\n";
    }
 
    try
    {
        long large = LONG_MAX;
        new int[large][1000];
    } 
    catch (const std::bad_array_new_length& e)
    {
        std::cout << "3) " << e.what() << ": too large\n";
    }
 
    std::cout << "End\n";
}

Possible output: 

1) std::bad_array_new_length: negative size
2) std::bad_array_new_length: too many initializers
3) std::bad_array_new_length: too large
End

See also

allocation functions
(function)
exception thrown when memory allocation fails
(class)
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