Don't try to catch every exception in every function

Reason

Catching an exception in a function that cannot take a meaningful recovery action leads to complexity and waste. Let an exception propagate until it reaches a function that can handle it. Let cleanup actions on the unwinding path be handled by RAII.

Example, don't

void f()   // bad
{
    try {
        // ...
    }
    catch (...) {
        // no action
        throw;   // propagate exception
    }
}

Enforcement

• Flag nested try-blocks.
• Flag source code files with a too high ratio of try-blocks to functions. (??? Problem: define "too high")