std::logic_error
Header: <stdexcept>
Defines a type of object to be thrown as exception. It reports errors that are a consequence of faulty logic within the program such as violating logical preconditions or class invariants and may be preventable.
# Declarations
class logic_error;
# Parameters
what_arg: explanatory stringother: another exception object to copy
# Return value
*this
# Notes
Because copying std::logic_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.
Before the resolution of LWG issue 254, the non-copy constructor can only accept std::string. It makes dynamic allocation mandatory in order to construct a std::string object.
After the resolution of LWG issue 471, 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.
# Defect reports
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 254 | C++98 | the constructor accepting const char* was missing | added |
| LWG 471 | C++98 | the explanatory strings of std::logic_error’scopies were implementation-defined | they are the same as that of theoriginal std::logic_error object |