C++ for Scientists - Technische Universität Dresden

244 CHAPTER 11. C++ LIBRARIES FOR SCIENTIFIC COMPUTING
We now briefly explain how the goals are met before entering a more detailed discussion of the
software design.
The GLAS should be considered as an interface to other software for linear algebra, e.g. the
BLAS, MTL, or other linear algebra software. Such interface is provided by the Back-ends,
whereas the syntax for using such backends does not change. For example, if we want to add a
scaled vector to another vector (an axpy), then we write
y + = a ∗ x ;
but the implementation can use the BLAS (e.g. daxpy), or MTL, or another package. We have
provided a reference C++ implementation, that is an illustration of how the expressions are
dispatched to the actual implementation.
The concepts mainly contain free functions and meta functions, so that external objects can be
used in GLAS provided these functions are specialized. As an exercise, we show how this can
be done for an std::vector.
For more information, see [?].
11.1.3 Status
GLAS is still under development. Currently, there are features for working with dense vectors
and matrices, and sparse matrices. There is support to the Boost.Sandbox.Bindings and Toolboxes
for working with LAPACK, Structured Matrices (mase toolbox), and iterative methods
(iterative toolbox).
11.2 Boost
Boost is a bit out of line in this chapter. Firstly, it is not a library itself but a whole collection
of freely available C ++ libraries. Secondly, not all of the contained libraries deal directly with
scientific computing. However, many of the “non-scientific” libraries provide useful functionality
for scientific libraries and applications.
Boost provides free portable C++ libraries.
Currently, the following Boost libraries are available that are useful for numerical software:
• Data structures
– tuple: pairs, triples, etc, e.g. tuple
– smart ptr: smart pointers
• Correctness and testing
– static assert: compile time assertions
• Template programming
– enable if, mpl, type traits
– static assert: compile time assertions