std::gslice
Template:cpp/numeric/valarray/sidebar
| Defined in header <valarray>
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| class gslice; |
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std::gslice is the selector class that identifies a subset of Template:cpp indices defined by a multi-level set of strides and sizes. Objects of type std::gslice can be used as indices with valarray's operator[] to select, for example, columns of a multidimensional array represented as a valarray.
Given the starting value s, a list of strides ij and a list of sizes dj, a std::gslice constructed from these values selects the set of indices kj=s+Σj(ijdj).
For example, a gslice with starting index 3, strides {19,4,1} and lengths {2,4,3} generates the following set of indices:
Template:cpp
It is possible to construct std::gslice objects that select some indices more than once: if the above example used the strides {1,1,1} , the indices would have been {3, 4, 5, 4, 5, 6, ...} . Such gslices may only be used as arguments to the const version of std::valarray::operator[], otherwise the behavior is undefined.
Member functions
| constructs a gslice (public member function) | |
| accesses the start of the gslice (public member function) | |
| accesses the array of strides of the gslice (public member function) | |
| accesses the array of sizees of the gslice (public member function) |
