fork download

#include <array>
#include <cstdint>
 
 
//
// Helpers..
//
template<unsigned> struct IntegerSize;
template<> struct IntegerSize<1> { typedef uint8_t Type; };
template<> struct IntegerSize<2> { typedef uint16_t Type; };
template<> struct IntegerSize<4> { typedef uint32_t Type; };
template<> struct IntegerSize<8> { typedef uint64_t Type; };
 
 
// Calculates the one's complement sum, but without the final bit flip.
// This allows you to call this method multiple times and flip the bits
// yourself after the last call.
template<typename T>
T OnesComplementSum(T t0, T t1)
{
    typedef typename IntegerSize<2 * sizeof(T)>::Type TemporaryResult;
    static const T cMaxValue = T(-1);
    static const unsigned cNumBits = 8 * sizeof(T);
 
    TemporaryResult sum = t0;
    sum += t1;
    while (sum > cMaxValue)
    {
        sum = (sum >> cNumBits) + (sum & cMaxValue);
    }
    return static_cast<T>(sum);
}
 
 
template<typename T, typename ...U>
T OnesComplementSum(T head, U ...tail)
{
    return OnesComplementSum(head, OnesComplementSum(tail...));
}
 
 
template<unsigned N> std::array<char, N> datum() { return std::array<char, N>(); }
 
int main()
{
	int a;
	long b;
	char c;
 
 
	OnesComplementSum(a, b, c);
}

prog.cpp: In function 'T OnesComplementSum(T, U ...) [with T = char, U = {}]':
prog.cpp:38:62:   instantiated from 'T OnesComplementSum(T, U ...) [with T = long int, U = {char}]'
prog.cpp:38:62:   instantiated from 'T OnesComplementSum(T, U ...) [with T = int, U = {long int, char}]'
prog.cpp:51:27:   instantiated from here
prog.cpp:38:62: error: no matching function for call to 'OnesComplementSum()'
prog.cpp: In function 'T OnesComplementSum(T, U ...) [with T = long int, U = {}]':
prog.cpp:38:62:   instantiated from 'T OnesComplementSum(T, U ...) [with T = int, U = {long int}]'
prog.cpp:38:62:   instantiated from 'T OnesComplementSum(T, U ...) [with T = int, U = {long int, char}]'
prog.cpp:51:27:   instantiated from here
prog.cpp:38:62: error: no matching function for call to 'OnesComplementSum()'

Standard output is empty