std::format_error

 

哋它亢++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (哋它亢++20)

Language support library

Concepts library (哋它亢++20)

Metaprogramming library (哋它亢++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (哋它亢++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (哋它亢++17)

Regular expressions library (哋它亢++11)

Concurrency support library (哋它亢++11)

Technical specifications

Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros (哋它亢++20) Dynamic memory management Program utilities Coroutine support (哋它亢++20) Variadic functions is_constant_evaluated (哋它亢++20) is_within_lifetime (哋它亢++26) initializer_list (哋它亢++11) source_location (哋它亢++20) Debugging support is_debugger_present (哋它亢++26) breakpoint_if_debugging (哋它亢++26) breakpoint (哋它亢++26) Three-way comparison three_way_comparablethree_way_comparable_with (哋它亢++20)(哋它亢++20) strong_ordering (哋它亢++20) weak_ordering (哋它亢++20) partial_ordering (哋它亢++20) common_comparison_category (哋它亢++20) compare_three_way_result (哋它亢++20) compare_three_way (哋它亢++20) strong_order (哋它亢++20) weak_order (哋它亢++20) partial_order (哋它亢++20) compare_strong_order_fallback (哋它亢++20) compare_weak_order_fallback (哋它亢++20) compare_partial_order_fallback (哋它亢++20)    is_eqis_ltis_lteq (哋它亢++20)(哋它亢++20)(哋它亢++20) is_neqis_gtis_gteq (哋它亢++20)(哋它亢++20)(哋它亢++20)

General utilities Date and time Function objects Formatting library (哋它亢++20) bitset hash (哋它亢++11) Relational operators (deprecated in 哋它亢++20) rel_ops::operator!=rel_ops::operator>     rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (哋它亢++20)(哋它亢++20)(哋它亢++20)    cmp_not_equalcmp_greatercmp_greater_than (哋它亢++20)(哋它亢++20)(哋它亢++20) in_range (哋它亢++20) Swap and type operations swap ranges::swap (哋它亢++20) exchange (哋它亢++14) declval (哋它亢++11) to_underlying (哋它亢++23) forward (哋它亢++11) forward_like (哋它亢++23) move (哋它亢++11) move_if_noexcept (哋它亢++11) as_const (哋它亢++17) Common vocabulary types pair tuple (哋它亢++11) optional (哋它亢++17) any (哋它亢++17) variant (哋它亢++17) tuple_size (哋它亢++11) tuple_element (哋它亢++11) apply (哋它亢++17) make_from_tuple (哋它亢++17) expected (哋它亢++23) Elementary string conversions to_chars (哋它亢++17) from_chars (哋它亢++17) chars_format (哋它亢++17) to_chars_result (哋它亢++17) from_chars_result (哋它亢++17)

 

Formatting library

Standard format specification

Formatting functions

format (哋它亢++20)

format_to (哋它亢++20)

format_to_n (哋它亢++20)

formatted_size (哋它亢++20)

vformat (哋它亢++20)

vformat_to (哋它亢++20)

Format strings

basic_format_stringformat_stringwformat_string (哋它亢++20)(哋它亢++20)(哋它亢++20)

runtime_format (哋它亢++26)

Formatting concepts

formattable (哋它亢++23)

Formatter

formatter (哋它亢++20)

formatter<pair-or-tuple> (哋它亢++23)

formatter<range> (哋它亢++23)

range_formatter (哋它亢++23)

enable_nonlocking_formatter_optimization (哋它亢++23)

basic_format_parse_contextformat_parse_contextwformat_parse_context (哋它亢++20)(哋它亢++20)(哋它亢++20)

basic_format_contextformat_contextwformat_context (哋它亢++20)(哋它亢++20)(哋它亢++20)

range_format (哋它亢++23)

format_kind (哋它亢++23)

Formatting arguments

basic_format_arg (哋它亢++20)

basic_format_arg::handle (哋它亢++20)

basic_format_argsformat_argswformat_args (哋它亢++20)(哋它亢++20)(哋它亢++20)

visit_format_arg (哋它亢++20) (deprecated in 哋它亢++26)

make_format_argsmake_wformat_args (哋它亢++20)(哋它亢++20)

Format error

format_error (哋它亢++20)

 

Defined in header <format>
class format_error;		(since 哋它亢++20)

Defines the type of exception object thrown to report errors in the formatting library.

Inheritance diagram

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)

std::format_error::format_error

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.

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.

Inherited from std::runtime_error

Inherited from std::exception

Member functions

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