On Fri, Dec 25, 2015 at 2:07 PM Masakatsu ITO(伊藤) <itoh.masakatsu@jaxa.jp> wrote:

Actually I tried to adapt my DiffereneceOperator type to Proto
as Proto Users Guide explains in "Adapting Existing Types to Proto".

http://www.boost.org/doc/libs/1_57_0/doc/html/proto/users_guide.html#boost_proto.users_guide.front_end.define_operators


I think this didn't work because the macro doesn't overload the function call operator.

 
And I wondered when it is necessary to write a code such like

calculator< proto::terminal< placeholder<0> >::type > const _1;

in "The extends< > Expression Wrapper".

http://www.boost.org/doc/libs/1_57_0/doc/html/proto/users_guide.html#boost_proto.users_guide.front_end.customizing_expressions_in_your_domain.extends


This is needed to make sure the terminal is part of the calculator domain, if you leave out the calculator<> part you just get an expression in the default domain.

 
Wishing you a merry Christmas,
Masa


Merry Christmas to you too!

Bart