On Wed, 19 Feb 2014 04:42:19 -0500, Daniel Murphy
<[email protected]> wrote:
"Steven Schveighoffer" wrote in message
news:[email protected]...
It may not be mindless. Most people who want to handle the default case
do it. It's usually not so much "I didn't think of handling other
values," it's more "I never expect other values to come in, go away
annoying compiler error."
So why not put an assert(0) in instead of a break? Tell the compiler
that you're assuming there are no other possible values. This is
obviously the right thing to do here, and even if you ignore it the
compiler _is_ trying to help you.
Putting default: assert(0); changes the meaning of the code. In other
words:
switch(x)
{
case 1: ...
}
is the same as:
switch(x)
{
case 1: ...
default: break;
}
You are keeping the code the same. I don't think people would think of
adding the assert(0), I wouldn't.
And as Ary pointed out, it may be that you expect the default to occur,
but don't want to do anything.
I think it's the same as saying you have to always have an else clause
after an if statement, even if it's "else {}"
If 'if' was primarily used for the same thing that switch is, this would
be perfectly reasonable.
'if' and 'switch' are commonly used interchangeably. Frequently one uses
'switch' where they would normally use 'if' to avoid evaluating something
multiple times.
-Steve
