On May 21, 2014 7:22:23 PM EDT, Vladimir Batov <Vladimir.Batov@constrainttec.com> wrote:
On 05/20/2014 09:58 PM, Andrzej Krzemienski wrote:
2014-05-20 6:34 GMT+02:00 Vladimir Batov <Vladimir.Batov@constrainttec.com>:
On 05/18/2014 11:45 PM, Vladimir Batov wrote:
Vladimir Batov <vb.mail.247 <at> gmail.com> writes:
Andrzej Krzemienski <akrzemi1 <at> gmail.com> writes:
It is an equivalent of a "monomorphic" lambda. I guess you could invent another syntax, that does not require to specify this InType:
convert<int>(cnv).value_or(-1);
which would render a converter object with parametrized signature:
template <typename InType> int operator()(const InType&);
I admit I have no slightest idea what "monomorphic lamda" is :-)
A single argument your lambda. [snip]
So far I only found boost::convert<std::string>(cnv));
has one limitation over
boost::convert<std::string, int>(cnv));
Namely, the latter can do implicit conversions when the former does not. That is, for the former to work correctly I have to have a container of elements the *correct* type. With the latter I can feed to an algorithm a container of elements *convertible* to the explicitly specified TypeIn.
That's where a polymorphic lambda comes into play: template<class T> std::string operator()(T); That function call operator can accept various types, yet produce the expected result. ___ Rob (Sent from my portable computation engine)