std::format_error(3)

💖 NAME 💖

std::format_error — std::format_error

okay so welcome to the C++ Standard Libary manual page for std::format_error(3), bestie 💅. Yes, that's literally the name twice; the vibes are immaculate and the facts are the facts.

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✨ Synopsis ✨

Defined in header <format>.

class format_error;         (since C++20)

So std::format_error defines the type of exception object thrown to report errors in the formatting library. It's giving "formatting went wrong, and we have thoughts" energy 😭.

The inheritance diagram asset is named std-format error-inheritance.svg, and its caption is Inheritance diagram.

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🎀 Member functions 🎀

• constructor — constructs a new format_error object with the given message (public member function).
• operator= — replaces the format_error object (public member function).

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💅 std::format_error::format_error

okay bestie, here are the three constructor flavors, all cute and accounted for:

format_error( const std::string& what_arg );        (1)
format_error( const char* what_arg );               (2)
format_error( const format_error& other ) noexcept; (3)

1. Constructs the exception object with what_arg as explanatory string. After construction, std::strcmp(what(), what_arg.c_str()) == 0.
2. Constructs the exception object with what_arg as explanatory string. After construction, std::strcmp(what(), what_arg) == 0.
3. Copy constructor. If *this and other both have dynamic type std::format_error then std::strcmp(what(), other.what()) == 0. No exception can be thrown from the copy constructor.

🌸 Parameters 🌸

• what_arg — explanatory string.
• other — another exception object to copy.

🔥 Exceptions 🔥

• 1,2) — May throw std::bad_alloc.

🌈 Notes 🌈

Because copying std::format_error is not permitted to throw exceptions, this message is typically stored internally as a separately-allocated reference-counted string. This is also why there is no constructor taking std::string&&: it would have to copy the content anyway.

A derived standard exception class must have a publicly accessible copy constructor. It can be implicitly defined as long as the explanatory strings obtained by what() are the same for the original object and the copied object.

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🦋 std::format_error::operator=

format_error& operator=( const format_error& other ) noexcept;

Assigns the contents with those of other. If *this and other both have dynamic type std::format_error then std::strcmp(what(), other.what()) == 0 after assignment. No exception can be thrown from the copy assignment operator.

💜 Parameters 💜

• other — another exception object to assign with.

⭐ Return value ⭐

*this

🍓 Notes 🍓

A derived standard exception class must have a publicly accessible copy assignment operator. It can be implicitly defined as long as the explanatory strings obtained by what() are the same for the original object and the copied object.

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🌈 Inherited from std::runtime_error

yep — inherited from std::runtime_error, bestie. That's the base-class pipeline 💅.

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🌈 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).

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🎀 Example 🎀

This section is incomplete.

Reason: no example.

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👀 See also 👀

🗂️ Category:

• Todo no example

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That's the whole page, bestie 🫶 — source http://cppreference.com, version/date 2024.06.10, manual page std::format_error(3). Bye 💋