Re: [Boost-users] [proto] baby steps learning with proto, proxy object

Subject: Re: [Boost-users] [proto] baby steps learning with proto, proxy object
From: Eric Niebler (eric_at_[hidden])
Date: 2010-10-08 15:31:00

On 10/7/2010 2:52 PM, alfC wrote:
<snip>
> So I guess we can create a proxy of the expression h[x] , "subindex of
> historgram with double". The proxy can be used with the syntax to call
> either accumulate or increment depending on the application of += or +
> + to the proxy.
> 
> The naive implementation is this:
> class histogram{
> 	...
> 	private:
> 	struct proxy_histogram_subscript{
> 		histogram& self;
> 		double const& x;
> 		proxy_histogram_subscript(histogram& self, double const& x) :
> self(self), x(x){}
> 		proxy_histogram_subscript const& operator++()
> const{self.increment(x); return *this;}
> 		bool operator++(int) const{return self.increment(x);}
> 		bool operator+=(double const& weight) const{return
> self.accumulate(x, weight);}
> 	};
> 	public:
> 	proxy_histogram_subscript operator[](double const& x){
> 		return proxy_histogram_subscript(*this, x);
> 	}
> };
> 
> which allows the desired syntax. The question is, can Boost.Proto do
> better?
<snip>

Not really, I don't think. What you have is short, simple, and
efficient. I wouldn't mess with it further.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com