A question about gmp_sprintf() and gmp_sscanf() functions

Paul Zimmermann Paul.Zimmermann at inria.fr
Wed Jul 29 20:53:43 UTC 2020


       Dear Ivan,

> Do you know whether 
> gmp_sprintf() and gmp_sscanf() functions can
> be used in a reversible manner. 
> 
> I mean, can we print a floating
> point number with a given precision in a string and than extract the same floating point number from the string.
> A want not to lose an information (even a bit). 

I don't know the answer for GMP, but for this kind of thing I would recommend
using the MPFR function mpfr_get_str with size N=0, which guarantees that if
you read back the generated string (with the same bit precision) you get the
same number.

Paul Zimmermann


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