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Hello there. I'd like to know if there's any reason for using generic template

template<typename T, typename WT> static void
mul_( const T* src1, size_t step1, const T* src2, size_t step2,
      T* dst, size_t step, Size size, WT scale )
{
    step1 /= sizeof(src1[0]);
    step2 /= sizeof(src2[0]);
    step /= sizeof(dst[0]);

    if( scale == (WT)1. )
    {
        for( ; size.height--; src1 += step1, src2 += step2, dst += step )
        {
            int i=0;
            #if CV_ENABLE_UNROLLED
            for(; i <= size.width - 4; i += 4 )
            {
                T t0;
                T t1;
                t0 = saturate_cast<T>(src1[i  ] * src2[i  ]);
                t1 = saturate_cast<T>(src1[i+1] * src2[i+1]);
                dst[i  ] = t0;
                dst[i+1] = t1;

                t0 = saturate_cast<T>(src1[i+2] * src2[i+2]);
                t1 = saturate_cast<T>(src1[i+3] * src2[i+3]);
                dst[i+2] = t0;
                dst[i+3] = t1;
            }
            #endif
            for( ; i < size.width; i++ )
                dst[i] = saturate_cast<T>(src1[i] * src2[i]);
        }
    }
    else
    {
        for( ; size.height--; src1 += step1, src2 += step2, dst += step )
        {
            int i = 0;
            #if CV_ENABLE_UNROLLED
            for(; i <= size.width - 4; i += 4 )
            {
                T t0 = saturate_cast<T>(scale*(WT)src1[i]*src2[i]);
                T t1 = saturate_cast<T>(scale*(WT)src1[i+1]*src2[i+1]);
                dst[i] = t0; dst[i+1] = t1;

                t0 = saturate_cast<T>(scale*(WT)src1[i+2]*src2[i+2]);
                t1 = saturate_cast<T>(scale*(WT)src1[i+3]*src2[i+3]);
                dst[i+2] = t0; dst[i+3] = t1;
            }
            #endif
            for( ; i < size.width; i++ )
                dst[i] = saturate_cast<T>(scale*(WT)src1[i]*src2[i]);
        }
    }
}

and not having partially-specified versions of this code which uses some of simd intrinsics? As far as I understand, this code (at least it's part inside of CV_ENABLE_UNROLLED) should be optimized by compiler, but e.g. MSVC 12.0 is unable to produce optimized code for T=uchar, because of saturation code that is used.