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252 lines
7.7 KiB
C++
252 lines
7.7 KiB
C++
#ifndef QDECCONTEXT_HH
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#define QDECCONTEXT_HH
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/** \file QDecContext.hh
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* Declarations for the class QDecContext.
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*
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* (C) Copyright Semih Cemiloglu
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* All rights reserved, see COPYRIGHT file for details.
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*
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* $Id$
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*
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*
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*/
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extern "C" {
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#include "decContext.h"
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}
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#include "QDecFwd.hh"
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// FORWARDS
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class QByteArray;
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class QTextStream;
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/*! Default context type or kind, should be set to one of these:
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* DEC_INIT_BASE
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* DEC_INIT_DECIMAL32
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* DEC_INIT_DECIMAL64
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* DEC_INIT_DECIMAL128
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*/
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const int QDecContextDefKind = DEC_INIT_BASE;
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//! Maximum precision allowed in precision (digits) field
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const int32_t QDecMaxPrecision = 999999999;
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const int32_t QDecMaxExponent = 999999999;
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const int32_t QDecMinExponent = -999999999;
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/*!
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\class QDecContext
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QDecContext encapsulates decContext structure as member and
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exposes free-standing functions as member functions.
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Most functions in the decNumber module take as an argument a
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decContext structure, which provides the context for operations
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(precision, rounding mode, etc.) and also controls the handling of
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exceptional conditions (corresponding to the flags and trap enablers
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in a hardware floating-point implementation).
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*/
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class QDECIMAL_EXPORT QDecContext
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{
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// MEMBERS
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//! Embedded decContext structure
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decContext m_data;
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public:
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// TYPES
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typedef decContext* decContextPtr_t;
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typedef enum rounding Rounding_e;
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// CREATORS
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//! Default constructor
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QDecContext(int32_t kind = QDecContextDefKind);
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QDecContext(const decContext* cptr) : m_data(*cptr) {}
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QDecContext(const decContext& data) : m_data(data) {}
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// Default Copy Ctor and Dtor and Copy assignment are ok
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// ACCESSORS
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//! Get decContext member
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const decContext* data() const
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{ return &m_data; }
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//! Get clamp flag of the context (IEEE exponent clamp)
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uint8_t clamp() const
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{ return m_data.clamp; }
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//! Get digits field of the context (working precision)
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int32_t digits() const
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{ return m_data.digits; }
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//! Get emax field of the context (maximum positive exponent)
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int32_t emax() const
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{ return m_data.emax; }
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//! Get emin field of the context (minimum negative exponent)
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int32_t emin() const
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{ return m_data.emin; }
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//! Get extended flag of the context (special values)
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uint8_t extended() const;
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//! Get round field of the context (rounding mode)
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Rounding_e round() const
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{ return m_data.round; }
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//! Get status flags of the context
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uint32_t status() const
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{ return m_data.status; }
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//! Get trap-enabler flags of the context
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uint32_t traps() const
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{ return m_data.traps; }
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// MODIFIERS
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//! Get decContext member
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decContext* data()
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{ return &m_data; }
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//! Set clamp flag of the context (IEEE exponent clamp)
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void setClamp(uint32_t clamp)
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{ m_data.clamp = clamp; }
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//! Set digits field of the context (working precision)
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void setDigits(int32_t digits)
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{ m_data.digits = digits; }
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//! Set emax field of the context (maximum positive exponent)
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void setEmax(int32_t emax)
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{ m_data.emax = emax; }
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//! Set emin field of the context (minimum negative exponent)
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void setEmin(int32_t emin)
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{ m_data.emin = emin; }
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//! Set extended flag of the context (special values)
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void setExtended(uint8_t ext);
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//! This function is used to return the round (rounding mode) field
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//! of a decContext.
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void setRound(Rounding_e round)
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{ m_data.round = round; }
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void setTraps(uint32_t traps)
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{ m_data.traps = traps; }
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/*!
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This function is used to set one or more status bits in the status
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field of a decContext. If any of the bits being set have the
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corresponding bit set in the traps field, a trap is raised
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(regardless of whether the bit is already set in the status field).
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Only one trap is raised even if more than one bit is being set.
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*/
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void setStatus(uint32_t status = 0)
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{ m_data.status = status; }
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//! This function is identical to setStatus except that
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//! the context traps field is ignored (i.e., no trap is raised).
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void setStatusQuiet(uint32_t status = 0)
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{ decContextSetStatusQuiet(&m_data, status); }
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// ROUTINES
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//! This function is used to clear (set to zero) one or more status
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//! bits in the status field of a decContext.
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QDecContext& clearStatus(uint32_t status)
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{ decContextClearStatus(&m_data, status); return *this; }
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//! This function is used to restore one or more status bits in
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//! the status field of a decContext from a saved status field.
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QDecContext& restoreStatus(uint32_t status, uint32_t mask)
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{ decContextRestoreStatus(&m_data, status, mask); return *this; }
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/*!
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This function is used to initialize a decContext structure to
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default values. It is stongly recommended that this function always
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be used to initialize a decContext structure, even if most or all
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of the fields are to be set explicitly (in case new fields are added
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to a later version of the structure).
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*/
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QDecContext& setDefault(int32_t kind = QDecContextDefKind)
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{ decContextDefault(&m_data, kind); return *this; }
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//! This function is used to save one or more status bits from
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//! the status field of a decContext.
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uint32_t saveStatus(uint32_t mask)
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{ return decContextSaveStatus(&m_data, mask); }
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/*!
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This function is used to set a status bit in the status field of a
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decContext, using the name of the bit as returned by the
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decContextStatusToString function. If the bit being set has the
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corresponding bit set in the traps field, a trap is raised
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(regardless of whether the bit is already set in the status field).
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*/
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QDecContext& setStatusFromString(const char* str)
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{ decContextSetStatusFromString(&m_data, str); return *this; }
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//! This function is identical to setStatusFromString except
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//! that the context traps field is ignored (i.e., no trap is raised).
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QDecContext& setStatusFromStringQuiet(const char* str)
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{ decContextSetStatusFromStringQuiet(&m_data, str); return *this; }
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//! This function returns a pointer (char *) to a human-readable
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//! description of a status bit. The string pointed to will be a constant.
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const char* statusToString() const
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{ return decContextStatusToString(&m_data); }
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//! This function is used to test one or more status bits in a context.
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uint32_t testStatus(uint32_t mask) //const
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{ return decContextTestStatus(&m_data, mask); }
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//! This function is used to clear (set to zero) all the
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//! status bits in the status field of a decContext.
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QDecContext& zeroStatus()
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{ decContextZeroStatus(&m_data); return *this; }
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// UTILITY ROUTINES
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//! Get status flags (fields) in string form
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//! separated by | character
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QByteArray statusFlags() const;
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//! Throw exception if status flags are set.
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void throwOnError() const
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{ if(m_data.status) throw(statusToString()); }
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//! Type conversion operator to decContext*
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operator decContextPtr_t() { return &m_data; }
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// STATIC FUNCTIONS
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//! This function checks that the DECLITEND tuning
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//! parameter is set correctly.
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//! Returns 0 if the DECLITEND parameter is correct,
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//! 1 if it is incorrect and should be set to 1, and
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//! -1 if it is incorrect and should be set to 0.
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static int TestEndian()
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{ return decContextTestEndian(1 /*Quiet*/); }
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//! This function is used to test one or more status
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//! bits in a saved status field.
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static uint32_t TestSavedStatus(uint32_t status, uint32_t mask)
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{ return decContextTestSavedStatus(status, mask); }
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}; // end class
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/*!
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QTextStream inserter to pretty-print QDecContext objects
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in the debug stream.
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*/
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QDECIMAL_EXPORT
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QTextStream& operator<<(QTextStream& ts, const QDecContext);
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//! Convience macro to extract decContext structure or
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//! create one on stack to comply with callee signature.
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#define CXT(cptr) ( cptr ? cptr->data() : QDecContext().data() )
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#endif /* Include guard */
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