Re: [Boost-bugs] [Boost C++ Libraries] #12299: User-defined conversion operator from a wrapper class to a boost/multiprecision floating-point type does not compile.

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #12299: User-defined conversion operator from a wrapper class to a boost/multiprecision floating-point type does not compile.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2016-06-24 19:58:57

#12299: User-defined conversion operator from a wrapper class to a
boost/multiprecision floating-point type does not compile.
-------------------------------------------+----------------------------
  Reporter:  Ulrich Mutze <ulrichmutze@…>  |      Owner:  johnmaddock
      Type:  Bugs                          |     Status:  new
 Milestone:  To Be Determined              |  Component:  multiprecision
   Version:  Boost 1.61.0                  |   Severity:  Problem
Resolution:                                |   Keywords:
-------------------------------------------+----------------------------

Comment (by anonymous):

 I'm having a hard time too understanding why my compiler does not respect
 what Stroustrup's 'The C++ programming language', 4th edition, says on the
 first half of p. 544. For exemplification he defines a class Tiny of small
 integers and endows it with the arithmetic facilities of type int by
 providing a member function Tiny::operator int()const which is asserted to
 effect implicit conversion (if a direct function call is not defined). Not
 being really familiar with the standard I simply googled 'conversion
 operator C++ standard' and got a page that seemed to me expressing the
 same in a more formal language.
 On the other hand, all my attempts to define 'R' as a simple self-made
 class, for which the intended
 type conversion would work, failed. So, the problem seems to be one of
 modern C++ implementations more than one of boost/multiprecision. However,
 it should be noted that (at least on my system) R1 works as intended for R
 defined as mpreal.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12299#comment:2>
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