std::chrono::ambiguous_local_time

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Defined in header`<chrono>`
class ambiguous_local_time;		(since C++20)

Defines a type of object to be thrown as exception to report that an attempt was made to convert an ambiguousstd::chrono::local_time to astd::chrono::sys_time without specifying astd::chrono::choose (such aschoose::earliest orchoose::latest).

This exception is thrown bystd::chrono::time_zone::to_sys and functions that call it (such as the constructors ofstd::chrono::zoned_time that take astd::chrono::local_time).

std-chrono-ambiguous local time-inheritance.svg

Inheritance diagram

[edit]Member functions

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

std::chrono::ambiguous_local_time::ambiguous_local_time

template<class Duration> ambiguous_local_time(conststd::chrono::local_time<Duration>& tp, conststd::chrono::local_info& i);	(1)	(since C++20)
ambiguous_local_time(const ambiguous_local_time& other)noexcept;	(2)	(since C++20)

Constructs the exception object.

1) The explanatory string returned bywhat() is equivalent to that produced byos.str() after the following code:

std::ostringstream os;os<< tp<<" is ambiguous.  It could be\n"<< tp<<' '<< i.first.abbrev<<" == "<< tp- i.first.offset<<" UTC or\n"<< tp<<' '<< i.second.abbrev<<" == "<< tp- i.second.offset<<" UTC";

The behavior is undefined ifi.result!= std::chrono::local_info::ambiguous.

2) Copy constructor. If*this andother both have dynamic typestd::chrono::ambiguous_local_time thenstd::strcmp(what(), other.what())==0.

Parameters

tp	-	the time point for which conversion was attempted
i	-	astd::chrono::local_info describing the result of the conversion attempt
other	-	another`ambiguous_local_time` to copy

Exceptions

May throwstd::bad_alloc

Notes

Because copying a standard library class derived fromstd::exception is not permitted to throw exceptions, this message is typically stored internally as a separately-allocated reference-counted string.

std::chrono::ambiguous_locale_time::operator=

ambiguous_locale_time& operator=(const ambiguous_locale_time& other)noexcept;		(since C++20)

Assigns the contents with those ofother. If*this andother both have dynamic typestd::chrono::ambiguous_locale_time thenstd::strcmp(what(), other.what())==0 after assignment.

Parameters

other

another exception object to assign with

Return value

*this

std::chrono::ambiguous_locale_time::what

virtualconstchar* what()constnoexcept;		(since C++20)

Returns the explanatory string.

Return value

Pointer to an implementation-defined null-terminated string with explanatory information. The string is suitable for conversion and display as astd::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 overridewhat().

Inherited fromstd::runtime_error

Inherited fromstd::exception

Member functions

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