CGAL 5.4 - Number Types
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#include <CGAL/Mpzf.h>
An object of the class Mpzf
is a multiple-precision floating-point number which can represent numbers of the form \( m*2^e\), where \( m\) is an arbitrary precision integer based on the GMP library, and \( e\) is of type int
.
This type can be considered exact, even if the exponent is not a multiple-precision number. A Mpzf
constructed from an integer or a normalized finite floating point number represents exactly that number. This number type offers functionality very similar to MP_Float
and Gmpzf
but is faster.
Implementation
This class is only available on platforms on which GMP uses 64 bit limbs and the endianness is either big-endian or little-endian. The macro CGAL_HAS_MPZF
will be defined when including CGAL/Mpzf.h
if this is true. This class makes the assumption that the representation of a double
in memory follows IEEE 754.
Currently, an Mpzf
contains an array of a few limbs, in which it stores the data as long as it fits. If it does not fit, it dynamically allocates memory with new, and de-allocates it when it is done. Code to recycle the allocated memory (per thread) is included but disabled at the moment.
Related Functions | |
(Note that these are not member functions.) | |
std::ostream & | operator<< (std::ostream &out, const Mpzf &f) |
writes a double approximation of f to the ostream out . | |
std::istream & | operator>> (std::istream &in, Mpzf &f) |
reads a double from in , then converts it to a Mpzf . | |
Creation | |
Mpzf () | |
creates a Mpzf initialized with 0 . | |
Mpzf (int i) | |
creates a Mpzf initialized with i . | |
Mpzf (long int l) | |
creates a Mpzf initialized with l . | |
Mpzf (const Gmpz &i) | |
creates a Mpzf initialized with i . | |
Mpzf (const mpz_class &i) | |
creates a Mpzf initialized with i . | |
Mpzf (double d) | |
creates a Mpzf initialized with d . | |
Conversion | |
operator Gmpq () const | |
creates a Gmpq initialized with *this . | |
operator mpq_class () const | |
creates a mpq_class initialized with *this . | |