Search results
Results from the WOW.Com Content Network
A typical vector implementation consists, internally, of a pointer to a dynamically allocated array, [1] and possibly data members holding the capacity and size of the vector. The size of the vector refers to the actual number of elements, while the capacity refers to the size of the internal array.
This constructor operates on three Vec; it allocates the necessary memory and then performs the computation. Thus only one memory allocation is performed. Example implementation of expression templates : An example implementation of expression templates looks like the following. A base class VecExpression represents any vector-valued expression.
More generally, there are d! possible orders for a given array, one for each permutation of dimensions (with row-major and column-order just 2 special cases), although the lists of stride values are not necessarily permutations of each other, e.g., in the 2-by-3 example above, the strides are (3,1) for row-major and (1,2) for column-major.
The C++11 standard has enhanced the allocator interface to allow "scoped" allocators, so that containers with "nested" memory allocations, such as vector of strings or a map of lists of sets of user-defined types, can ensure that all memory is sourced from the container's allocator.
An array with stride of exactly the same size as the size of each of its elements is contiguous in memory. Such arrays are sometimes said to have unit stride . Unit stride arrays are sometimes more efficient than non-unit stride arrays, but non-unit stride arrays can be more efficient for 2D or multi-dimensional arrays , depending on the ...
Structure of arrays (SoA) is a layout separating elements of a record (or 'struct' in the C programming language) into one parallel array per field. [1] The motivation is easier manipulation with packed SIMD instructions in most instruction set architectures, since a single SIMD register can load homogeneous data, possibly transferred by a wide internal datapath (e.g. 128-bit).
Permute (and Shuffle) instructions, part of bit manipulation as well as vector processing, copy unaltered contents from a source array to a destination array, where the indices are specified by a second source array. [1] The size (bitwidth) of the source elements is not restricted but remains the same as the destination size.
The C++ Standard Library provides several generic containers, functions to use and manipulate these containers, function objects, generic strings and streams (including interactive and file I/O), support for some language features, and functions for common tasks such as finding the square root of a number. The C++ Standard Library also ...