206 lines
9.9 KiB
C++
206 lines
9.9 KiB
C++
/*
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* compiletime_functions.hpp
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* Akupara
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*
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* Created by Udi on 12/19/06.
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*
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*/
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#if !defined(_AKUPARA_COMPILETIME_FUNCTIONS_HPP__INCLUDED_)
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#define _AKUPARA_COMPILETIME_FUNCTIONS_HPP__INCLUDED_
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//#include "WavesPublicAPIs/wstdint.h"
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namespace Akupara
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{
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// For templates that "return" a value, use template_name<arguments>::value
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// For templates that "return" a type, use template_name<arguments>::type
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// Integer log2 functions
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//------------------------------------------------------------------------
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template<unsigned int n>
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struct compiletime_bit_count_to_represent { static const unsigned int value = 1+compiletime_bit_count_to_represent<(n>>1)>::value; };
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template<>
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struct compiletime_bit_count_to_represent<0> { static const unsigned int value = 0; };
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//------------------------------------------------------------------------
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template<unsigned int n>
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struct compiletime_log2_ceiling { static const unsigned int value=compiletime_bit_count_to_represent<n-1>::value; };
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template<>
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struct compiletime_log2_ceiling<0> {}; // no value for 0 argument
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//------------------------------------------------------------------------
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template<unsigned int n>
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struct compiletime_log2_floor { static const unsigned int value=compiletime_bit_count_to_represent<n>::value-1; };
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template<>
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struct compiletime_log2_floor<0> {}; // no value for 0 argument
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//------------------------------------------------------------------------
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// Assertion - accessing 'value' will generate a compile-time error if the argument evaluates to false
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//------------------------------------------------------------------------
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template<bool>
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struct compiletime_assert;
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template<>
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struct compiletime_assert<true> { static const bool value=true; };
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template<>
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struct compiletime_assert<false> {}; // no value member for false assertion -> compile time error
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//------------------------------------------------------------------------
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// Select type - selects one of two types based on a boolean
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//------------------------------------------------------------------------
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template<bool, typename, typename>
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struct compiletime_select_type;
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template<typename _true_type, typename _false_type>
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struct compiletime_select_type<true, _true_type, _false_type> { typedef _true_type type; };
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template<typename _true_type, typename _false_type>
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struct compiletime_select_type<false, _true_type, _false_type> { typedef _false_type type; };
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//------------------------------------------------------------------------
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// Integer types by byte count
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//------------------------------------------------------------------------
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namespace detail
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{
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template<unsigned int _size, bool _signed>
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struct integer_with_byte_count_base;
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template<>
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struct integer_with_byte_count_base<1,true> { typedef int8_t type; };
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template<>
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struct integer_with_byte_count_base<2,true> { typedef int16_t type; };
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template<>
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struct integer_with_byte_count_base<4,true> { typedef int32_t type; };
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template<>
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struct integer_with_byte_count_base<8,true> { typedef int64_t type; };
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template<>
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struct integer_with_byte_count_base<1,false> { typedef uint8_t type; };
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template<>
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struct integer_with_byte_count_base<2,false> { typedef uint16_t type; };
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template<>
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struct integer_with_byte_count_base<4,false> { typedef uint32_t type; };
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template<>
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struct integer_with_byte_count_base<8,false> { typedef uint64_t type; };
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} // namespace detail
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//------------------------------------------------------------------------
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template<unsigned int _size, bool _signed=true>
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struct integer_with_byte_count : public detail::integer_with_byte_count_base<_size,_signed>
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{
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typedef typename detail::integer_with_byte_count_base<_size,_signed>::type type; // not required but makes the statement below less messy
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static const bool s_correct_size = compiletime_assert<sizeof(type)==_size>::value; // if you get a compilation error here then integer_with_byte_count is not defined correctly
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};
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//------------------------------------------------------------------------
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template<unsigned int _size>
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struct signed_integer_with_byte_count : public integer_with_byte_count<_size,true> {};
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template<unsigned int _size>
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struct unsigned_integer_with_byte_count : public integer_with_byte_count<_size,false> {};
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//------------------------------------------------------------------------
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// The following are TR1 compatible, until we get decent TR1 library support on all platforms
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//------------------------------------------------------------------------
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template<typename _T, _T _v>
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struct integral_constant
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{
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static const _T value = _v;
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typedef _T value_type;
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typedef integral_constant<_T, _v> type;
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}; // struct integral_constant
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typedef integral_constant<bool, false> false_type;
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typedef integral_constant<bool, true > true_type;
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//------------------------------------------------------------------------
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template<typename _T, typename _U> struct is_same : public false_type {};
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template<typename _T> struct is_same<_T,_T> : public true_type {};
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//------------------------------------------------------------------------
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// These are NOT TR1 but make use of some TR1 stuff
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//------------------------------------------------------------------------
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namespace detail
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{
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struct no_type; // if you end up getting this type, it means that you asked for something that doesn't exist
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template<unsigned int _pair_index> struct signed_unsigned_pair;
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#define AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(index, base_type_name) \
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template<> struct signed_unsigned_pair<index> { typedef signed base_type_name signed_type; typedef unsigned base_type_name unsigned_type; };
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#define AKUPARA_SIGNED_UNSIGNED_FLOAT_PAIR(index, type_name) \
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template<> struct signed_unsigned_pair<index> { typedef type_name signed_type; typedef no_type unsigned_type; };
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AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(1, char )
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AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(2, short )
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AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(3, int )
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//AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(4, int32_t )// 64BitConversion
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template<>
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struct
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signed_unsigned_pair<4>
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{
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typedef int32_t signed_type;
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typedef uint32_t unsigned_type;
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};
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AKUPARA_SIGNED_UNSIGNED_INTEGER_PAIR(5, long long)
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AKUPARA_SIGNED_UNSIGNED_FLOAT_PAIR (6, float )
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AKUPARA_SIGNED_UNSIGNED_FLOAT_PAIR (7, double )
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AKUPARA_SIGNED_UNSIGNED_FLOAT_PAIR (8, long double)
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const unsigned int k_signed_unsigned_pair_count = 8;
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// eliminate the no_type type
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template<typename _T> struct filtered_type { typedef _T type; };
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template<> struct filtered_type<no_type> {}; // no type defined
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// search for _T in signed type list
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template<unsigned int _index, typename _T> struct find_in_signed_type_list_from_index
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{
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static const unsigned int value = is_same< _T, typename signed_unsigned_pair<_index>::signed_type >::value ? _index : find_in_signed_type_list_from_index<_index-1,_T>::value;
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};
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template<typename _T> struct find_in_signed_type_list_from_index<0, _T> { static const unsigned int value = 0; };
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template<typename _T> struct find_in_signed_type_list : public find_in_signed_type_list_from_index<k_signed_unsigned_pair_count, _T> {};
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// search for _T in unsigned type list
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template<unsigned int _index, typename _T> struct find_in_unsigned_type_list_from_index
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{
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static const unsigned int value = is_same< _T, typename signed_unsigned_pair<_index>::unsigned_type >::value ? _index : find_in_unsigned_type_list_from_index<_index-1,_T>::value;
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};
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template<typename _T> struct find_in_unsigned_type_list_from_index<0, _T> { static const unsigned int value = 0; };
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template<typename _T> struct find_in_unsigned_type_list : public find_in_unsigned_type_list_from_index<k_signed_unsigned_pair_count, _T> {};
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template<bool _is_signed, bool _is_unsigned, typename _T> struct equivalent_signed_type;
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template<typename _T> struct equivalent_signed_type <true, false, _T> { typedef _T type; };
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template<typename _T> struct equivalent_signed_type <false, true, _T> { typedef typename filtered_type< typename signed_unsigned_pair< find_in_unsigned_type_list<_T>::value >::signed_type >::type type; };
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template<bool _is_signed, bool _is_unsigned, typename _T> struct equivalent_unsigned_type;
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template<typename _T> struct equivalent_unsigned_type<true, false, _T> { typedef typename filtered_type< typename signed_unsigned_pair< find_in_signed_type_list<_T>::value >::unsigned_type >::type type; };
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template<typename _T> struct equivalent_unsigned_type<false, true, _T> { typedef _T type; };
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} // namespace detail
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//------------------------------------------------------------------------
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template<typename _T> struct is_signed { static const bool value = detail::find_in_signed_type_list <_T>::value != 0; };
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template<typename _T> struct is_unsigned { static const bool value = detail::find_in_unsigned_type_list<_T>::value != 0; };
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//------------------------------------------------------------------------
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template<typename _T> struct equivalent_signed_type : public detail::equivalent_signed_type < is_signed<_T>::value, is_unsigned<_T>::value, _T > {};
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template<typename _T> struct equivalent_unsigned_type : public detail::equivalent_unsigned_type< is_signed<_T>::value, is_unsigned<_T>::value, _T > {};
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//------------------------------------------------------------------------
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} // namespace Akupara
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#endif // _AKUPARA_COMPILETIME_FUNCTIONS_HPP__INCLUDED_
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