Re: [Boost-users] [signals] signal-signal connections and thread-safety

On Saturday 10 February 2007 07:11 pm, Timmo Stange wrote:

Frank Mori Hess wrote:

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Yes, that'd be nice. I think a non-throwing partial specialization (or a simulated one for compilers that don't support it) of last_value would be good.

If I'm following, you're saying something like

last_value would be like the current last_value<T> and last_value would be like last_optional<T>? It seems easier just to provide a stand-alone last_optional<T> since the implementation of last_value<T> is so trivial.

No, I meant a partial specialization for optional<T> directly, i.e. last_value. That makes the return value of that function object (in our case the combiner) "optional", which reflects the intention to have it not throwing for an empty input range pretty well, I think.

The work-around for compilers lacking partial specialization is to give the specialization a different class name, right (e.g. last_optional<T>)? So providing a partial specialization would result in last_value

throwing when compiled on some compilers and not on others. It seems less confusing to provide last_optional<T> only.

-- Frank