std::future_error::what

From cppreference.com
< cpp‎ | thread‎ | future error
virtual const char* what() const;
(since C++11)

Returns the explanatory string.

Parameters

(none)

Return value

Pointer to a null-terminated string with explanatory information.

Exceptions

noexcept specification:  
noexcept
  

See also

returns the error code
(public member function)