It's okay for your C++ code if it's:
- Compiled with exceptions enabled.
- Exception safe.
It's okay for your C or C++ code if:
- No resources need to be collected explicitly between the throwing of the exception, and its being caught.
Code compiled with C++ exception support adds special hooks to clean up when exceptions are thrown and not caught in that scope. C++ objects allocated on the stack will have their destructors invoked.
The only resource reclaimed in C (or C++ without exception support) when an exception is thrown is the space allocated in each stack frame.
This section of the GCC manual is quite helpful:
-fexceptions
Enable exception handling. Generates extra code needed to
propagate exceptions. For some targets, this implies GCC will
generate frame unwind information for all functions, which can
produce significant data size overhead, although it does not affect
execution. If you do not specify this option, GCC will enable it
by default for languages like C++ which normally require exception
handling, and disable it for languages like C that do not normally
require it. However, you may need to enable this option when
compiling C code that needs to interoperate properly with exception
handlers written in C++. You may also wish to disable this option
if you are compiling older C++ programs that don't use exception
handling.
