Re: [boost] [conversion] try_lexical_cast and 200$

On 12/12/2013 19:45, Quoth Michael Caisse:

On 12/11/2013 10:34 PM, Gavin Lambert wrote:

...

Also having to specify both types is more annoying than in the bool form, where the compiler can infer the parameters.

You still just write:

out1 = try_lexical_cast<T1>(in1)

where the type of out1 is optional<T1> and the type of in1 is deduced.

I thought that ought to work, but I wrote a toy example and it didn't, which is why I phrased it like that. Thinking back on it now I realise what the problem was: On 12/12/2013 18:41, Quoth Peter Dimov:

Antony Polukhin wrote:

...

And if yes, what signature is preffered:

bool try_lexical_cast(Out&, const In&) bool try_lexical_cast(const In&, Out&) boost::optional<Out> try_lexical_cast(const In&)

bool try_lexical_cast(const In&, Out&), I'd say.

Inference requires the ordering of template parameters (for the optional version; it doesn't matter for the bool version). I had them wrong when testing my toy. My apologies for the noise.