template specialization according to sizeof type

Question

I would like to provide a templated function, that varies its implementation (->specialization) according to the sizeof the template type.

Something similar to this (omi

Answer 1

I can propose the following method: Its benefit is that you don't have to throw an exception if the operand isn't of the valid size. It just won't link. So that you have the error checking at build time.

template
void byteswapInPlace(void* p);

template<> void byteswapInPlace<1>(void* p) { /* do nothing */ }

template<> void byteswapInPlace<2>(void* p)
{
    _byteswap_ushort((ushort*) p);
}

template<> void byteswapInPlace<4>(void* p)
{
    _byteswap_ulong((ulong*) p);
}

template<> void byteswapInPlace<8>(void* p)
{
    _byteswap_uint64((uint64*) p);
}


template
T byteswap(T & swapIt)
{
    byteswapInPlace(&swapIt);
    return swapIt;
}