libcruft-util/fixed.hpp

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/*
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* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
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* Copyright 2011-2014 Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include "types/sized.hpp"
#include "maths.hpp"
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#include <iosfwd>
namespace cruft {
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template <
// whether the type is signed or unsigned. supply an appropriately
// signed type here; it won't be used for anything else.
typename T,
// how many bits total are used for the integral component
unsigned I,
// how many bits are used for the fractional component
unsigned E
>
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class [[gnu::packed]] fixed {
public:
static_assert (I > 0);
static_assert (E > 0);
static_assert ((I + E) % 8 == 0);
using sint_t = typename types::sized::bits<I+E>::sint;
using uint_t = typename types::sized::bits<I+E>::uint;
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using native_type = typename std::conditional<
std::is_signed<T>::value,
sint_t, uint_t
>::type;
using integer_type = typename std::conditional<
std::is_signed<T>::value,
typename types::sized::bits<divup (I, 8u) * 8u>::sint,
typename types::sized::bits<divup (I, 8u) * 8u>::uint
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>::type;
explicit fixed (double);
explicit fixed (float);
double to_double (void) const;
float to_float (void) const;
integer_type to_integer (void) const;
native_type to_native (void) const;
static fixed<T,I,E> from_native (native_type);
static fixed<T,I,E> from_integer (integer_type);
static integer_type to_integer (native_type);
fixed<T,I,E>& operator +=(const fixed<T,I,E>);
fixed<T,I,E>& operator -=(const fixed<T,I,E>);
fixed<T,I,E>& operator *=(const fixed<T,I,E>);
fixed<T,I,E>& operator /=(const fixed<T,I,E>);
fixed<T,I,E> operator +(const fixed<T,I,E>) const;
fixed<T,I,E> operator -(const fixed<T,I,E>) const;
fixed<T,I,E> operator *(const fixed<T,I,E>) const;
fixed<T,I,E> operator /(const fixed<T,I,E>) const;
fixed<T,I,E>& operator +=(integer_type);
fixed<T,I,E>& operator -=(integer_type);
fixed<T,I,E>& operator *=(integer_type);
fixed<T,I,E>& operator /=(integer_type);
fixed<T,I,E> operator +(integer_type) const;
fixed<T,I,E> operator -(integer_type) const;
fixed<T,I,E> operator *(integer_type) const;
fixed<T,I,E> operator /(integer_type) const;
private:
fixed () = default;
native_type m_value;
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};
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template <typename T, unsigned I, unsigned E>
constexpr
fixed<T,I,E>
bswap (fixed<T,I,E> val)
{
return fixed<T,I,E>::from_native (
bswap (val.to_native ())
);
}
template <typename T, unsigned I, unsigned E> bool operator== (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
template <typename T, unsigned I, unsigned E> bool operator!= (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
template <typename T, unsigned I, unsigned E> bool operator< (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
template <typename T, unsigned I, unsigned E> bool operator<= (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
template <typename T, unsigned I, unsigned E> bool operator> (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
template <typename T, unsigned I, unsigned E> bool operator>= (cruft::fixed<T,I,E>, cruft::fixed<T,I,E>);
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template <typename T, unsigned I, unsigned E> bool operator== (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
template <typename T, unsigned I, unsigned E> bool operator!= (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
template <typename T, unsigned I, unsigned E> bool operator< (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
template <typename T, unsigned I, unsigned E> bool operator<= (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
template <typename T, unsigned I, unsigned E> bool operator> (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
template <typename T, unsigned I, unsigned E> bool operator>= (cruft::fixed<T,I,E>, typename cruft::fixed<T,I,E>::integer_type);
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template <typename T, unsigned I, unsigned E>
std::ostream& operator<< (std::ostream&, fixed<T,I,E>);
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}