Developer Guide and Reference

Contents

n_index_generator

To facilitate simpler creation of
n_index_t
objects, the generator object
n_index
is provided.

Syntax

template<typename... TypeListT> class n_index_generator; namespace { // Instance of generator object n_index_generator<> n_index; }
Description
The generator object provides recursively constructing operators [] for
fixed<>
,
aligned<>
, and
integer
values allowing building of a
n_index_t<…>
instance one dimension at a time. Its main purpose is to allow a usage syntax that is similar to C multi-dimensional array definition.
Compare the following examples, instantiating three
n_index_t
instances, and using the generator object to instantiate equivalent instances.
n_index_t<int, int> idx1(row, col); n_index_t<int, aligned<16>> idx2(row, aligned<16>(col)); n_index_t<fixed<540>, fixed<960>> idx3(540_fixed, 960_fixed);
auto idx1 = n_index[row][col]; auto idx2 = n_index[row][aligned<16>(col)]; auto idx3 = n_index[540_fixed][960_fixed];
Class Hierarchy
It is expected that
n_index_generator
< … > not be directly used as a data member or parameter, instead only
n_index_t
<...> from which it is derived. The generator object
n_index
can be automatically downcast any place expecting an
n_index_t<…>
.
The following table provides the template arguments for
n_index_generator
Template Argument
Description
typename... TypeListT
Comma separated list of types, where the number of types provided controls how many dimensions the generator currently represents. Each type in the list identifies how the size of the corresponding dimension is to be represented. The order of the dimensions is the same order as C++ subscripts declaring a multi-dimensional array – from leftmost to rightmost.
Requirements
: Type is
int
,
fixed<NumberT>
, or
aligned<AlignmentT>
.
The following table provides information on the types defined as members of
n_index_generator
in addition to those inherited from
n_index_t
.
Member Type
Description
typedef n_index_t<TypeListT...> value_type
Type value that the any chained [] operator calls have produced.
The following table provides information on the members of
n_index_generator
in addition to those inherited from
n_index_t
Member
Description
n_index_generator ()
Requirements:
TypeListT is empty.
Effects:
Construct generator with no indices specified.
n_index_generator (const n_index_generator &a_other)
Effects:
Construct generator copying any index values from a_other
n_index_generator<TypeListT..., int> operator [] (int a_index) const
Requirements:
a_size >= 0.
Returns:
n_index_generator<…> with additional rightmost integer based index.
n_index_generator<TypeListT..., fixed<NumberT>> operator [] (fixed<NumberT> a_index) const
Requirements:
a_size >= 0.
Returns:
n_index_generator<…> with additional rightmost fixed<NumberT> index.
n_index_generator<TypeListT..., aligned<AlignmentT>> operator [] (aligned<AlignmentT> a_index)
Requirements:
a_size >= 0
Returns:
n_index_generator<…> with additional rightmost aligned<AlignmentT> based index.
value_type value() const
Returns:
n_extent_t<…> with the correct types and values of the multi-dimensional extents aggregated by the generator.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804