NAME¶

std::exception::exception - std::exception::exception

Synopsis¶

exception() throw(); (until C++11)
exception() noexcept; (1) (since C++11)
exception( const exception& other ) throw(); (2) (until C++11)
exception( const exception& other ) noexcept; (since C++11)

Constructs new exception object.

1) Default constructor. what() returns an implementation-defined string.
2) Copy constructor. Initializes the contents with those of other. If *this and
other both have dynamic type std::exception then std::strcmp(what(), other.what())
== 0.

Parameters¶

other - another exception to assign the contents of

Notes¶

Because copying std::exception is not permitted to throw exceptions, when derived
classes (such as std::runtime_error) have to manage a user-defined diagnostic
message, it is typically implemented as a copy-on-write string.

The Microsoft implementation includes non-standard constructors taking strings thus
allowing instances to be thrown directly with a meaningful error message. The
nearest standard equivalents are std::runtime_error or std::logic_error.

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 471 C++98 there is no requirement on what() of the added
exception copy