Re: [Boost-users] multiprecision -- eigen matrices using dynamically allocated variable-precision mpfr_float

Subject: Re: [Boost-users] multiprecision -- eigen matrices using dynamically allocated variable-precision mpfr_float
From: John Maddock (jz.maddock_at_[hidden])
Date: 2015-04-16 14:21:48

On 15/04/2015 19:35, Daniel Brake wrote:
> Hi John,
>
> > Can you try building with BOOST_NO_CXX11_RVALUE_REFERENCES defined 
> and see if that fixes the issue?
>
> I assumed you meant to compile my executable, not all of boost and 
> then my executable.  I have attempted to compile my program with 
> #define BOOST_NO_CXX11_RVALUE_REFERENCES, defined prior to my 
> #inclusions, and I get two compiler errors.  I'm using 
> clang-600.0.57.  Here are the errors:
>

Never mind, false lead anyway - there's a bug in the assignment operator 
of mpfr_float_backend - the operator:

mpfr_float_backend& operator=(const mpfr_float_backend& o)

Needs to be a no-op in the case of self-assignment, otherwise the call 
to mpfr_set_prec sets the value to NaN, even though the precision and 
value doesn't actually change in this case :(

There'll be an official patch shortly, but I need to wait for the 
revised tests to complete first (to make sure they catch this).

John.