constructing rationals from mpfr_floats [multiprecision]

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constructing rationals from mpfr_floats [multiprecision]

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1)  I am getting signaling due to division by 0.  The following lines are faulty:

    mpfr_float p("1.1");
    mpq_rational q(p);

signal: integer divide by zero;

whereas this succeeds:

    mpq_rational q(1.1);

any one seen this before?  i'm on compiler Apple LLVM version 8.0.0 (clang-800.0.38) ,with homebrew-provided boost 1.64, mpfr 3.1.5, gmp 6.1.2.


2)  I also expected to be able to construct rationals as

    mpq_rational q("1.1")

but it fails to parse using the built-in constructor.  i mean, i understand why (1.1 isn't a rational), but given that i can construct a rational from a double, i figured that i'd get something reasonable from "1.1", namely 11/10.



dani brake
university of wisconsin eau claire

ps i am not disabling mixed double-multiprecision arithmetic in this scenario, in case you have been reading my other questions this last week

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