opencv/3rdparty/openexr/Imath/ImathLimits.h
2012-10-17 15:57:49 +04:00

268 lines
7.7 KiB
C++

///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Industrial Light & Magic nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
///////////////////////////////////////////////////////////////////////////
#ifndef INCLUDED_IMATHLIMITS_H
#define INCLUDED_IMATHLIMITS_H
//----------------------------------------------------------------
//
// Limitations of the basic C++ numerical data types
//
//----------------------------------------------------------------
#include <float.h>
#include <limits.h>
//------------------------------------------
// In Windows, min and max are macros. Yay.
//------------------------------------------
#if defined _WIN32 || defined _WIN64
#ifdef min
#undef min
#endif
#ifdef max
#undef max
#endif
#endif
namespace Imath {
//-----------------------------------------------------------------
//
// Template class limits<T> returns information about the limits
// of numerical data type T:
//
// min() largest possible negative value of type T
//
// max() largest possible positive value of type T
//
// smallest() smallest possible positive value of type T
// (for float and double: smallest normalized
// positive value)
//
// epsilon() smallest possible e of type T, for which
// 1 + e != 1
//
// isIntegral() returns true if T is an integral type
//
// isSigned() returns true if T is signed
//
// Class limits<T> is useful to implement template classes or
// functions which depend on the limits of a numerical type
// which is not known in advance; for example:
//
// template <class T> max (T x[], int n)
// {
// T m = limits<T>::min();
//
// for (int i = 0; i < n; i++)
// if (m < x[i])
// m = x[i];
//
// return m;
// }
//
// Class limits<T> has been implemented for the following types:
//
// char, signed char, unsigned char
// short, unsigned short
// int, unsigned int
// long, unsigned long
// float
// double
// long double
//
// Class limits<T> has only static member functions, all of which
// are implemented as inlines. No objects of type limits<T> are
// ever created.
//
//-----------------------------------------------------------------
template <class T> struct limits
{
static T min();
static T max();
static T smallest();
static T epsilon();
static bool isIntegral();
static bool isSigned();
};
//---------------
// Implementation
//---------------
template <>
struct limits <char>
{
static char min() {return CHAR_MIN;}
static char max() {return CHAR_MAX;}
static char smallest() {return 1;}
static char epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return (char) ~0 < 0;}
};
template <>
struct limits <signed char>
{
static signed char min() {return SCHAR_MIN;}
static signed char max() {return SCHAR_MAX;}
static signed char smallest() {return 1;}
static signed char epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return true;}
};
template <>
struct limits <unsigned char>
{
static unsigned char min() {return 0;}
static unsigned char max() {return UCHAR_MAX;}
static unsigned char smallest() {return 1;}
static unsigned char epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return false;}
};
template <>
struct limits <short>
{
static short min() {return SHRT_MIN;}
static short max() {return SHRT_MAX;}
static short smallest() {return 1;}
static short epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return true;}
};
template <>
struct limits <unsigned short>
{
static unsigned short min() {return 0;}
static unsigned short max() {return USHRT_MAX;}
static unsigned short smallest() {return 1;}
static unsigned short epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return false;}
};
template <>
struct limits <int>
{
static int min() {return INT_MIN;}
static int max() {return INT_MAX;}
static int smallest() {return 1;}
static int epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return true;}
};
template <>
struct limits <unsigned int>
{
static unsigned int min() {return 0;}
static unsigned int max() {return UINT_MAX;}
static unsigned int smallest() {return 1;}
static unsigned int epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return false;}
};
template <>
struct limits <long>
{
static long min() {return LONG_MIN;}
static long max() {return LONG_MAX;}
static long smallest() {return 1;}
static long epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return true;}
};
template <>
struct limits <unsigned long>
{
static unsigned long min() {return 0;}
static unsigned long max() {return ULONG_MAX;}
static unsigned long smallest() {return 1;}
static unsigned long epsilon() {return 1;}
static bool isIntegral() {return true;}
static bool isSigned() {return false;}
};
template <>
struct limits <float>
{
static float min() {return -FLT_MAX;}
static float max() {return FLT_MAX;}
static float smallest() {return FLT_MIN;}
static float epsilon() {return FLT_EPSILON;}
static bool isIntegral() {return false;}
static bool isSigned() {return true;}
};
template <>
struct limits <double>
{
static double min() {return -DBL_MAX;}
static double max() {return DBL_MAX;}
static double smallest() {return DBL_MIN;}
static double epsilon() {return DBL_EPSILON;}
static bool isIntegral() {return false;}
static bool isSigned() {return true;}
};
template <>
struct limits <long double>
{
static long double min() {return -LDBL_MAX;}
static long double max() {return LDBL_MAX;}
static long double smallest() {return LDBL_MIN;}
static long double epsilon() {return LDBL_EPSILON;}
static bool isIntegral() {return false;}
static bool isSigned() {return true;}
};
} // namespace Imath
#endif