experimental

CppCon 2014 Costless Software Abstractions for Parallel Architectures—Joel Falcou

Have you registered for CppCon 2015 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Costless Software Abstractions for Parallel Architectures

by Joel Falcou

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Performing large, intensive or non-trivial computing on array like data structures is one of the most common task in scientific computing, video game development and other fields. This matter of fact is backed up by the large number of tools, languages and libraries to perform such tasks. If we restrict ourselves to C++ based solutions, more than a dozen such libraries exists from BLAS/LAPACK C++ binding to template meta-programming based Blitz++ or Eigen. If all of these libraries provide good performance or good abstraction, none of them seems to fit the need of so many different user types.

Moreover, as parallel system complexity grows, the need to maintain all those components quickly become unwieldy. This talk explores various software design techniques - like Generative Programming, MetaProgramming and Generic Programming - and their application to the implementation of a parallel computing librariy in such a way that:

- abstraction and expressiveness are maximized - cost over efficiency is minimized

We'll skim over various applications and see how they can benefit from such tools. We will conclude by discussing what lessons were learnt from this kind of implementation and how those lessons can translate into new directions for the language itself.

CppCon 2014 Making Allocators Work, Part IIā€”Alisdair Meredith

Have you registered for CppCon 2015 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Making Allocators Work, Part II

by Alisdair Meredith

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Memory is an important property for every object, as whatever resources it manages, it must occupy some memory. THe ability to customize memory allocation is important for every C++ program that cares about performance, debug ability and support.

The original C++ standard supported an allocator parameter for every container, yet this feature was widely derided or ignored, as it was underspecified to the point it could not portably be used. C++11 makes significant changes to the allocator model, that simply its use while making it more powerful.

The Library Fundamentals TS goes further, allowing allocators’ type to be supplied at runtime, rather than compile type, using classic object oriented polymorphism - yet building on the infrastructure laid down in C++11.

This material should be of interest to both library authors and consumers, although clearly there are more details for the implementers to absorb. It also includes an interesting case study in C++11 compile time reflection, as required to implement the new ‘allocator_traits’ facility.

CppCon 2014 Making Allocators Work, Part I—Alisdair Meredith

Have you registered for CppCon 2015 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Making Allocators Work, Part I

by Alisdair Meredith

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Memory is an important property for every object, as whatever resources it manages, it must occupy some memory. THe ability to customize memory allocation is important for every C++ program that cares about performance, debug ability and support.

The original C++ standard supported an allocator parameter for every container, yet this feature was widely derided or ignored, as it was underspecified to the point it could not portably be used. C++11 makes significant changes to the allocator model, that simply its use while making it more powerful.

The Library Fundamentals TS goes further, allowing allocators' type to be supplied at runtime, rather than compile type, using classic object oriented polymorphism - yet building on the infrastructure laid down in C++11.

This material should be of interest to both library authors and consumers, although clearly there are more details for the implementers to absorb. It also includes an interesting case study in C++11 compile time reflection, as required to implement the new 'allocator_traits' facility.

CppCon 2014 What the committee did next!—Alisdair Meredith

Have you registered for CppCon 2015 in September? Don’t delay – Early Bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

What the committee did next!

by Alisdair Meredith

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Now that C++14 is done, what is the standard committee working on next?

After inking 8 years to produce the C++11 standard (arguably 13) there was a feeling we should be able to produce new work faster, more incrementally. With the renewed interest in C++, we have more participation on the committee, and have looked to harness that enthusiasm in new ways. In the last 3 years we have spun up at least a dozen new study groups, and have 8 or mode Technical Specifications in various stages of development that we hope to ship over the next 12-24 months. So what are all these new groups and specifications about? Come to this session and get a vision of where C++ is headed in the immediate and short-term future.

CppCon 2014 Parallelizing the Standard Algorithms Library—Jared Hoberock

Have you registered for CppCon 2015 in September? Don’t delay – Early Bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Parallelizing the Standard Algorithms Library

by Jared Hoberock

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Until recently, C++ programmers building parallel programs found little support for parallelism in the standard toolbox. That's changing with the technical specification on Extensions for Parallelism in C++. This talk will explore how programmers can build portable parallel programs from high-level parallel algorithms which can execute on CPU threads, vector units, and even GPUs.

Folding Expressions—Marco Alesiani

A new blog post containing runnable code from the Italian C++ Community:

Folding Expressions

by Marco Alesiani

From the article:

C++17, scheduled by 2017 at the time of writing, will introduce fold expressions into play and significantly broaden parameter packs scopes of use [...]

template<typename F, typename... T>
void for_each(F fun, T&&... args)
{
    (fun (std::forward<T>(args)), ...);
}

The sample above uses fold expressions together with the comma operator to create a simple function that calls the provided lambda per each one of the supplied arguments with perfect forwarding. [...]

HPX and C++ Dataflow(await)—Hartmut Kaiser

Uses/Implementation/Discussion about await feature in modern C++.

HPX and C++ Dataflow

by Hartmut Kaiser

From the article:

We have done some experiments with a preliminary implementation of await in Visual Studio 2015RC. We were able to integrate it well with the futures in HPX and the results are very promising. Unfortunately, the await keyword (and resumable functions) will only be available in all mainstream compilers years from today. So for now we will have to make do with our poor-man’s-await –dataflow.

In any case, if you want to try things out (including dataflow), please fork HPX from our Github site and tell us what you think.

CppCon 2014 What did C++ do for Transactional Memory?—Michael Wong

Have you registered for CppCon 2015 in September? Don’t delay – Early Bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

What did C++ do for Transactional Memory?

by Michael Wong

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

SG5 is a Study Group within WG21 developing a promising new way to deal with mutable shared memory, that is expected to be more usable and scalable than current techniques based on atomics and mutexes. It promises to be as easy to use as coarse-grained locks, as scalable as fine-grained locks and yet remain composable.

Find out where on the Gartner hype cycle lives Transactional Memory.
Is it at the Peak of Inflated Expectations, Trough of Disillusionment, Slope of Enlightenment, or Plateau of Productivity?

For that matter, just how soon will I be able to use it with the new Intel Haswell, and IBM Power Hardware, or is it one of those mirages where the closer you get to your hardware, the further it moves away.

And is it true that one of the lead author of this TM proposal also wrote "Is it just a Research Toy?"

This 60 minute advanced talk will cover the history of Transactional Memory, various lock elision and optimistic speculation techniques, the technical engine behind Transactional Memory, the recent research in its use cases, usability and performance data that supports its entry into the C++ Standard, and of course the latest details of the SG5 Technical Specification, including our effort at transactionalizing the C++ Standard Library.

CppCon 2014 Modern Template Metaprogramming: A Compendium, Part II—Walter E. Brown

Have you registered for CppCon 2015 in September? Don’t delay – Early Bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Modern Template Metaprogramming: A Compendium, Part II

by Walter E. Brown

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Template metaprogramming has become an important part of a C++ programmer's toolkit. This talk will demonstrate state-of-the-art metaprogramming techniques, applying each to obtain representative implementations of selected standard library facilities.

Along the way, we will look at void_t, a recently-proposed, extremely simple new new type_traits candidate whose use has been described by one expert as "highly advanced (and elegant), and surprising even to experienced template metaprogrammers."

CppCon 2014 Modern Template Metaprogramming: A Compendium, Part I—Walter E. Brown

Have you registered for CppCon 2015 in September? Don’t delay – Early Bird registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2014 for you to enjoy. Here is today’s feature:

Modern Template Metaprogramming: A Compendium, Part I

by Walter E. Brown

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Template metaprogramming has become an important part of a C++ programmer's toolkit. This talk will demonstrate state-of-the-art metaprogramming techniques, applying each to obtain representative implementations of selected standard library facilities.

Along the way, we will look at void_t, a recently-proposed, extremely simple new new type_traits candidate whose use has been described by one expert as "highly advanced (and elegant), and surprising even to experienced template metaprogrammers."