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45 lines
1.9 KiB
Plaintext
45 lines
1.9 KiB
Plaintext
[/
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Copyright 2021 - 2025 Fahad Syed.
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Copyright 2025 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:cpp_double_fp_ref cpp_double_fp_backend]
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namespace boost{ namespace multiprecision {
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template <class FloatingPointType>
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class cpp_double_fp_backend;
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typedef number<cpp_double_fp_backend<float>, et_off> cpp_double_float;
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typedef number<cpp_double_fp_backend<double>, et_off> cpp_double_double;
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typedef number<cpp_double_fp_backend<long double>, et_off> cpp_double_long_double;
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typedef number<cpp_double_fp_backend<boost::float128_type>, et_off> cpp_double_float128; // Only when boost::float128_type is available
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}} // namespaces
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The `cpp_double_fp_backend` back-end is the sum of two IEEE floating-point numbers
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combined to create a type having roughly twice the composite width of one of its parts.
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The `cpp_double_fp_backend` back-end is used in conjunction with `number`
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and acts as an entirely C++ header only floating-point number type.
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Class template `cpp_double_fp_backend` fulfills 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 one template parameter:
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[variablelist
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[[FloatingPointType][The constituent IEEE floating-point value of the two limbs of the composite type.
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This can be `float`, `double`, `long double` or when available `boost::float128_type`.]]
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]
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The type of `number_category<cpp_dec_float<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.cpp_double_fp_backend tutorial].
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[endsect]
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