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/* -*- c++ -*- */
/*
* Copyright (C) 2010 The Android Open Source Project
* 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.
*
* 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 ANDROID_ASTL_LIMITS__
#define ANDROID_ASTL_LIMITS__
#include <limits.h>
// GNU C++ compiler?
#ifndef __GNUG__
#error "__GNUG__ is not defined"
#endif
#ifdef _T
#error "_T is defined"
#endif
// This is very incomplete partial implementation of the standard
// <limits>. Only partial support for float and double is provided.
namespace {
// Template to return the number of decimal digits in a number
// representation based on the number of bits and sign.
// e.g digits10<int,64,true>::value == 19
template<typename T, T bits, bool is_signed> struct digits10 {
static const int value = 0;
};
// Specialization that can be used to initialize static constant at
// compile time.
template<> struct digits10<int, 8, false> { static const int value = 3; };
template<> struct digits10<int, 8, true> { static const int value = 3; };
template<> struct digits10<int, 16, false> { static const int value = 5; };
template<> struct digits10<int, 16, true> { static const int value = 5; };
template<> struct digits10<int, 32, false> { static const int value = 10; };
template<> struct digits10<int, 32, true> { static const int value = 10; };
template<> struct digits10<int, 64, false> { static const int value = 20; };
template<> struct digits10<int, 64, true> { static const int value = 19; };
}
namespace std {
struct __numeric_limits_base
{
// True for all fundamental types.
static const bool is_specialized = false;
// True if the type is signed.
static const bool is_signed = false;
// True if the type is integer.
static const bool is_integer = false;
// The number of radix digits that be represented without change. For
// integer types, the number of non-sign bits in the representation; for
// floating-point types, the number of radix digits in the mantissa.
// Equivalent to FLT_MANT_DIG, DBL_MANT_DIG.
static const int digits = 0;
// The number of base 10 digits that can be represented without change.
// Equivalent to FLT_DIG, DBL_DIG, LDBL_MANT_DIG.
static const int digits10 = 0;
};
// Properties of fundamental types.
// Only a subset of the properties is supported.
template<typename _T>
struct numeric_limits : public __numeric_limits_base
{
// The minimum finite value.
static _T min() { return static_cast<_T>(0); }
// The maximum finite value.
static _T max() { return static_cast<_T>(0); }
};
// Specializations for some fundamental types.
// numeric_limits<float>
template<>
struct numeric_limits<float>
{
static const bool is_specialized = true;
static float min() { return __FLT_MIN__; }
static float max() { return __FLT_MAX__; }
static const bool is_signed = true;
static const bool is_integer = false;
static const int digits = __FLT_MANT_DIG__;
static const int digits10 = __FLT_DIG__;
};
// numeric_limits<double>
template<>
struct numeric_limits<double>
{
static const bool is_specialized = true;
static double min() { return __DBL_MIN__; }
static double max() { return __DBL_MAX__; }
static const bool is_signed = true;
static const bool is_integer = false;
static const int digits = __DBL_MANT_DIG__;
static const int digits10 = __DBL_DIG__;
};
// numeric_limits<int>
template<>
struct numeric_limits<int>
{
static const bool is_specialized = true;
static int min() { return INT_MIN; }
static int max() { return INT_MAX; }
static const bool is_signed = true;
static const bool is_integer = true;
static const int digits = static_cast<int>(sizeof(int) * CHAR_BIT);
static const int digits10 = digits10<int, digits, is_signed>::value;
};
// numeric_limits<unsigned int>
template<>
struct numeric_limits<unsigned int>
{
static const bool is_specialized = true;
static unsigned int min() { return 0; }
static unsigned int max() { return UINT_MAX; }
static const bool is_signed = false;
static const bool is_integer = true;
static const int digits = static_cast<int>(sizeof(unsigned int) * CHAR_BIT);
static const int digits10 = digits10<int, digits, is_signed>::value;
};
// numeric_limits<long>
template<>
struct numeric_limits<long>
{
static const bool is_specialized = true;
static long min() { return LONG_MIN; }
static long max() { return LONG_MAX; }
static const bool is_signed = true;
static const bool is_integer = true;
static const int digits = LONG_BIT;
static const int digits10 = digits10<int, digits, is_signed>::value;
};
// numeric_limits<unsigned long>
template<>
struct numeric_limits<unsigned long>
{
static const bool is_specialized = true;
static unsigned long min() { return 0; }
static unsigned long max() { return ULONG_MAX; }
static const bool is_signed = true;
static const bool is_integer = true;
static const int digits = LONG_BIT;
static const int digits10 = digits10<int, digits, is_signed>::value;
};
// numeric_limits<long long>
template<>
struct numeric_limits<long long>
{
static const bool is_specialized = true;
static long long min() { return LLONG_MIN; }
static long long max() { return LLONG_MAX; }
static const bool is_signed = true;
static const bool is_integer = true;
static const int digits = static_cast<int>(sizeof(long long) * CHAR_BIT);
static const int digits10 = digits10<int, digits, is_signed>::value;
};
// numeric_limits<unsigned long long>
template<>
struct numeric_limits<unsigned long long>
{
static const bool is_specialized = true;
static unsigned long long min() { return 0; }
static unsigned long long max() { return ULLONG_MAX; }
static const bool is_signed = true;
static const bool is_integer = true;
static const int digits = static_cast<int>(sizeof(unsigned long long) * CHAR_BIT);
static const int digits10 = digits10<int, digits, is_signed>::value;
};
} // namespace std
#endif