* This behavior of this class is made similar to the basic data types double
* and float. The definition of a vectorized array does not initialize the
* data field but rather leaves it undefined, as is the case for double and
- * float. However, when calling something like VectorizedArray<double> a =
- * VectorizedArray<double>(), it sets all numbers in this field to zero. In
- * other words, this class is a plain old data (POD) type which has an
- * equivalent C representation and can e.g. be safely copied with std::memcpy.
- * This POD layout is also necessary for ensuring correct alignment of data
- * with address boundaries when collected in a vector (i.e., when the first
- * element in a vector is properly aligned, all subsequent elements will be
- * correctly aligned, too).
+ * float. However, when calling something like `VectorizedArray<double> a =
+ * VectorizedArray<double>()` or `VectorizedArray<double> a = 0.`, it sets all
+ * numbers in this field to zero. This class is of standard layout type
+ * according to the C++11 standard, which means that there is an equivalent C
+ * representation and the class can e.g. be safely copied with std::memcpy.
+ * The standard layout is also necessary for ensuring correct alignment of
+ * data with address boundaries when collected in a vector (i.e., when the
+ * first element in a vector is properly aligned, all subsequent elements will
+ * be correctly aligned, too).
*
* Note that for proper functioning of this class, certain data alignment
* rules must be respected. This is because the computer expects the starting
* (usually, the address of the vectorized array should be a multiple of the
* length of the array in bytes). Otherwise, a segmentation fault or a severe
* loss of performance might occur. When creating a single data field on the
- * stack like <tt>VectorizedArray<double> a = VectorizedArray<double>()</tt>,
- * the compiler will take care of data alignment automatically. However, when
- * allocating a long vector of VectorizedArray<double> data, one needs to
- * respect these rules. Use the class AlignedVector or data containers based
- * on AlignedVector (such as Table) for this purpose. It is a class very
- * similar to std::vector otherwise but always makes sure that data is
- * correctly aligned.
+ * stack like `VectorizedArray<double> a = 5.;`, the compiler will take care
+ * of data alignment automatically. However, when allocating a long vector of
+ * VectorizedArray<double> data, one needs to respect these rules. Use the
+ * class AlignedVector or data containers based on AlignedVector (such as
+ * Table) for this purpose. It is a class very similar to std::vector
+ * otherwise but always makes sure that data is correctly aligned.
*
* The user can explicitly control the width of a particular instruction set
* architecture (ISA) extension by specifying the number of lanes via the second
static_assert(width == n_array_elements,
"You specified an illegal width that is not supported.");
- // POD means that there should be no user-defined constructors, destructors
- // and copy functions (the standard is somewhat relaxed in C++2011, though).
-
/**
* Default empty constructor, leaving the data in an uninitialized state
* similar to float/double.
}
/**
- * Actual data field. Since this class represents a POD data type, it is
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
* declared public.
*/
Number data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m512d data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m512 data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m256d data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m256 data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m128d data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__m128 data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__vector double data;
}
/**
- * Actual data field. Since this class represents a POD data type, it
- * remains public.
+ * Actual data field. To be consistent with the standard layout type and to
+ * enable interaction with external SIMD functionality, this member is
+ * declared public.
*/
__vector float data;
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