std::exception::what

 

C++

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

 

Diagnostics library

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Exception categories logic_error invalid_argument domain_error length_error out_of_range runtime_error range_error overflow_error underflow_error tx_exception (TM TS) System error error_category (C++11) generic_category (C++11) system_category (C++11) error_condition (C++11) errc (C++11) error_code (C++11) system_error (C++11) Stacktrace stacktrace_entry (C++23) basic_stacktrace (C++23) Debugging support is_debugger_present (C++26) breakpoint_if_debugging (C++26) breakpoint (C++26)

 

std::exception

Member functions

exception::exception

exception::~exception

exception::operator=

exception::what

 

virtual const char* what() const throw();		(until C++11)
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 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 on the exception object is called.

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

(since C++26)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 108	C++98	it was unspecified when the returned pointer becomes invalid	specified