signBit()

signBit(i) provides a fast way to determine the value of the sign bit (as a bool) for integral and floating types. More...

Functions
bool	SimTK::signBit (unsigned char u)
bool	SimTK::signBit (unsigned short u)
bool	SimTK::signBit (unsigned int u)
bool	SimTK::signBit (unsigned long u)
bool	SimTK::signBit (unsigned long long u)
bool	SimTK::signBit (signed char i)
bool	SimTK::signBit (short i)
bool	SimTK::signBit (int i)
bool	SimTK::signBit (long long i)
bool	SimTK::signBit (long i)
bool	SimTK::signBit (const float &f)
bool	SimTK::signBit (const double &d)
bool	SimTK::signBit (const negator< float > &nf)
bool	SimTK::signBit (const negator< double > &nd)

Detailed Description

signBit(i) provides a fast way to determine the value of the sign bit (as a bool) for integral and floating types.

Note that this is significantly different than sign(x); be sure you know what you're doing if you use this method. signBit() refers to the underlying representation rather than the numerical value. For example, for floating types there are two zeroes, +0 and -0 which have opposite sign bits but the same sign (0). Also, unsigned types have sign() of 0 or 1, but they are considered here to have a sign bit of 0 always, since the stored high bit does not indicate a negative value.

Notes

• signBit() is overloaded for 'signed char' and 'unsigned char', but not for plain 'char' because we don't know whether to interpret the high bit as a sign in that case (because the C++ standard leaves it unspecified).
• complex and conjugate numbers do not have sign bits.
• negator<float> and negator<double> have the same sign bit as the underlying representation – it's up to you to realize that it is interpreted differently!

See Also

sign()

Function Documentation

bool SimTK::signBit ( unsigned char  u )

inline

bool SimTK::signBit ( unsigned short  u )

inline

bool SimTK::signBit ( unsigned int  u )

inline

bool SimTK::signBit ( unsigned long  u )

inline

bool SimTK::signBit ( unsigned long long  u )

inline

bool SimTK::signBit ( signed char  i )

inline

bool SimTK::signBit ( short  i )

inline

bool SimTK::signBit ( int  i )

inline

bool SimTK::signBit ( long long  i )

inline

bool SimTK::signBit ( long  i )

inline

bool SimTK::signBit ( const float &  f )

inline

bool SimTK::signBit ( const double &  d )

inline

bool SimTK::signBit ( const negator< float > &  nf )

inline

bool SimTK::signBit ( const negator< double > &  nd )

inline