41 lines
1.8 KiB
Plaintext
41 lines
1.8 KiB
Plaintext
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[/
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Copyright 2011 - 2020 John Maddock.
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Copyright 2013 - 2019 Paul A. Bristow.
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Copyright 2013 Christopher Kormanyos.
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt).
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]
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[section:mpfr_ref mpfr_float_backend]
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namespace boost{ namespace multiprecision{
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template <unsigned Digits10>
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class mpfr_float_backend;
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typedef number<mpfr_float_backend<50> > mpfr_float_50;
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typedef number<mpfr_float_backend<100> > mpfr_float_100;
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typedef number<mpfr_float_backend<500> > mpfr_float_500;
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typedef number<mpfr_float_backend<1000> > mpfr_float_1000;
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typedef number<mpfr_float_backend<0> > mpfr_float;
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}} // namespaces
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Class template `mpfr_float_backend` fulfils all of the requirements for a [link boost_multiprecision.ref.backendconc Backend] type.
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Its members and non-member functions are deliberately not documented: these are considered implementation details that are subject
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to change.
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The class takes a single template parameter - `Digits10` - which is the number of decimal digits precision the type
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should support. When this parameter is zero, then the precision can be set at runtime via `number::default_precision`
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and `number::precision`. Note that this type does not in any way change the GMP or MPFR library's global state (for example
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it does not change the default precision of the mpfr_t data type), therefore you can safely mix this type with existing
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code that uses GMP or MPFR, and also mix `mpfr_float_backend`s of differing precision.
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The type of `number_category<cpp_int<Args...> >::type` is `std::integral_constant<int, number_kind_floating_point>`.
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More information on this type can be found in the [link boost_multiprecision.tut.floats.mpfr_float tutorial].
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[endsect]
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