Re: [boost] [Assign] list_of comma operator removed?

From: Thorsten Ottosen (tottosen_at_[hidden])
Date: 2006-02-16 16:05:35

Jon Willesen wrote:
> I recently attempted to upgrade from boost 1.32.0 to boost 1.33.1 got received
> some compiler errors from boost.assign.
> 
> My most common usage of boost::assign looks like this:
> 
> vector<string> data = (list_of<string>(), "foo", "bar", "baz");
> 
> I like this better than the alternative syntax (elements delimeted by
> parentheses) because I can type it more quickly and it more closely resembles
> array initialization syntax, which makes it more likely that my coworkers, who
> aren't as familiar with boost, will understand what's going on.

ok.

> But it appears my compiler errors were caused by the removal of the comma
> operator in the class the list_of function returns.  It appears this was
> intentional since the unit tests were changed, but the current documentation
> for list_of still indicates the comma operator is legal syntax, and
> operator+= still uses the comma syntax, so I'm a little confused.

My memory is weak in this respect, but I think I might have viewed the 
syntax as redundant.

If you like the comma, you might write

data += "foo", "bar", "baz";

but that is not initialization.

I don't mind adding the operator again, it should be trivially defined, 
but I wonder if we removed it because it could actually create problems
in some situations.

-Thorsten