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

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

On 12/12/2013 18:41, Quoth Peter Dimov:

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...

optional<> is cute because you can use if( auto x = try_lexical_cast<Out>(in) ), but not very convenient for the common case of try_lexical_cast(in1, out1) && try_lexical_cast(in2, out2).

Optional would work in that case too, eg:

if ((out1 = try_lexical_cast(in1)) && (out2 = try_lexical_cast(in2))) { // both casts worked, do something with out1 and out2 }

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

(I'm not really a fan of output parameters either, but c'est la vie.)

On the other hand, if it's not going to resemble "result = name<T>(source)" then it's not very cast-like, so the name seems a little odd now. But not enough to bother me much. :)

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. -- Michael Caisse ciere consulting ciere.com