std::bad_array_new_length(3)

💅 NAME 💅

Okay bestie, you're on the manual page for std::bad_array_new_length — from the C++ Standard Libary manual, section 3 — and the original NAME line is literally std::bad_array_new_length - std::bad_array_new_length (the name, the whole name, and nothing but the name, we love a minimalist moment 💀). This page is all about the exception type for invalid array lengths, no cap ✨.

🌸 SYNOPSIS 🌸

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. 🫶

There's also an inheritance diagram file called std-bad array new length-inheritance.svg, labeled Inheritance diagram — very demure, very visual 🌈.

💖 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 )
(2) (since C++11)
noexcept;

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 )
(since C++11)
noexcept;

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)

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(). Ngl, that's the whole note — don't start drama about it 😌.

👑 INHERITED FROM std::bad_alloc 👑

This page says Inherited from std::bad_alloc — that's the note, bestie. 🫶

💜 INHERITED FROM std::exception 💜

🌸 MEMBER FUNCTIONS 🌸

• destructor — destroys the exception object [virtual] (virtual public member function of std::exception)
• what — returns an explanatory string [virtual] (virtual public member function of std::exception)

🔥 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 💅

• operator new — allocation functions
• operator new[] — (function)
• bad_alloc — exception thrown when memory allocation fails (class)

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🌸 source/version/date sign-off, bestie: http://cppreference.com · 2024.06.10 · std::bad_array_new_length(3) — bye, go catch those invalid array lengths 💖✨