This is a draft version of a MISRA C++ 202x rule proposed for public review.
MISRA Rule 18.1.2
Category: Required
Analysis Type: Decidable,Single Translation Unit
Amplification
An empty throw is a throw-expression with no operand.
For the purposes of this rule, the body of a lambda declared within the compound-statement of a catch handler is not considered
to be part of the catch handler.
Rationale
An empty throw re-throws the temporary object that represents an exception. Its use is intended to enable the handling of an exception to
be split across two or more handlers.
Syntactically, there is nothing to prevent an empty throw from being used outside a catch handler. However, this would result in
implementation-defined program termination when there is no exception object to re-throw.
Example
void f1( void )
{
try
{
throw std::range_error( "range error" );
}
catch ( std::exception const & )
{
log( "Caught in f1" );
throw; // Compliant - re-throws an exception object
}
}
void f2( void )
{
throw; // Non-compliant - not syntactically within a catch
}
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