try-catch syntax and rules

A try block must use braces {} and has its own scope.

A try block must be followed by one or more catch blocks.

A catch block must use braces {} and is a scope.

Each catch block must have a declaration list

Declaration lists declare one type, with an optional identifier.

The catch block can treat the identifier like a local variable.

catch block identifiers shadow other local variables.

It is possible to catch *any* exception:

void f()
{
    try
    {
        acct.withdraw( 2000000 );
    }
    catch ( ... )
    {
        // free dynamic memory:
        delete[] my_temp_array;
        throw;
    }
}