boost

The Case for Optional References—Tristan Brindle

And why not simply use a pointer?

The Case for Optional References

by Tristan Brindle

From the article:

I have a confession to make. Whenever I’ve come across code that looks like this:

struct example {
    example() = default;

    example(std::string& s) : str_{s} {}

private:
    boost::optional<std::string&> str_{};
};

there is a little voice inside my head that whispers “why didn’t you just use a pointer?”. Like so, for instance:

struct example {
    example() = default;

    example(std::string& s) : str_{&s} {}

private:
    std::string* str_ = nullptr;
};

This is equivalent to the first example, except that it’s slightly less typing, it doesn’t have any dependencies, and feels in some sense “cleaner”. I personally have always preferred it.

Except, I was wrong. After attending Bjarne Stroustrup’s keynote and this excellent talk at Cppcon this morning, I’m persuaded that optional references are a good thing. In this post I hope to be able to convince you of the same...

CppCon 2015 Boost Units Library for Correct Code—Robert Ramey

Have you registered for CppCon 2016 in September? Don’t delay – Late registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2015 for you to enjoy. Here is today’s feature:

Boost Units Library for Correct Code

by Robert Ramey

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

I will give a presentation on the Boost Units library.

This library implements a zero runtime facility for performing dimensional analysis checking and automatic units conversion on C++ expressions. I have found this indispensable for coding scientific programs involving a variety of complex physical units. The documentation of the Boost Units library is totally complete and accurate, but totally inpenetrable. I had to spend way too much time figuring out how to use this. By attending this meeting, you're going to avoid this pain and just get the benefit of simpler programs that contain fewer bugs.

CppCon 2015 Racing The File System—Niall Douglas

Have you registered for CppCon 2016 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 2015 for you to enjoy. Here is today’s feature:

Racing The File System

by Niall Douglas

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Almost every programmer knows about and fears race conditions on memory where one strand of execution may concurrently update data in use by another strand of execution, leading to an inconsistent and usually dangerous inconsistent read of program state. Almost every programmer therefore is aware of mutexes, memory ordering, semaphores and the other techniques used to serialise access to memory.

Interestingly, most programmers are but vaguely aware of potential race conditions on the filing system, and as a result write code which assumes that the filing system does not suddenly change out from underneath you when you are working on it. This assumption of a static filing system introduces many potential security bugs never mind ways of crashing your program, and of course creating data loss and corruption.

This workshop will cover some of the ways in which filing system races can confound, and what portable idioms and patterns you should employ to prevent misoperation, even across networked Samba shares. Finally, an introduction of the proposed Boost library AFIO will be made which can help application developers writing filing system race free code portably.

CppCon 2015 Reflection Techniques in C++—Paul Fultz II

Have you registered for CppCon 2016 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 2015 for you to enjoy. Here is today’s feature:

Reflection Techniques in C++

by Paul Fultz II

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Reflection is a very powerful and useful feature used in many languages to achieve things like serialization, object-relationship mapping, and general data-driven development. C++ doesn't support reflection natively in the language yet. There are proposals to add compile-time reflection to the language, but C++ has survived all this time without direct support for reflection.

This talk will discuss the various techniques the can be used to achieve reflection including boost fusion, the visitor patter, and do-it-yourself with some macros and metaprogramming. This talk will discuss how these techniques can be used to implement serialization or object-relational mapping.

An update on the Meeting C++ Workshop Day

I finally can announce that the workshops will end with talks by James McNellis and Michael Caisse:

An Update on the workshop day

by Jens Weller

From the article:

Michael Caisse - boost.fusion: power to the tuples

    Tuples provide heterogeneous, compile-time containers; however, they can be difficult to use at run-time. Boost.Fusion brings together compile-time and run-time semantics to produce the STL of the meta-programming world. It is the machinery behind several Boost libraries and is a common element in many of the solutions provided by Ciere Consulting.


James McNellis - Practical C++ Coroutines

    One of the most interesting new features being proposed for C++ standardization is coroutines, formerly known as “resumable functions”. C++ coroutines are designed to be highly scalable, highly efficient (no overhead), and highly extensible, while still interacting seamlessly with the rest of the C++ language.

CppCon 2015 Integrating generators EDSL’s for Spirit X3 (WIP)—Feliple Magno de Almeida

Have you registered for CppCon 2016 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 2015 for you to enjoy. Here is today’s feature:

Integrating generators EDSL's for Spirit X3 (WIP)

by Feliple Magno de Almeida

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Based on the presentation I made on C++Now 2015 for Developing EDSL's for Boost.Spirit V2, present the development of generators for Boost.Spirit X3 (next version of boost spirit) and how that can be used for higher abstraction EDSL's while, through template metaprogramming, create parsers and generators automatically from the same grammar, using CORBA format as an example, while dealing with endianness, alignment and asymmetric grammars. This work is based on the library mORBid (https://github.com/expertisesolutions...) and (https://github.com/expertisesolutions...).

Meeting C++ 2016: closing keynote & full schedule

With the announcement of the closing keynote the full schedule for Meeting C++ 2016 stands!

Closing keynote & full schedule of Meeting C++ 2016

by Jens Weller

From the article:

Since mid of June the program of the 5th Meeting C++ conference was taking shape. With the selection of the talks it was also clear in which tracks they go, so that the schedule it self was almost ready, except a last detail: the closing keynote.

The closing keynote will be held by Louis Dionne on "C++ metaprogramming: evolution and future directions".

boost 1.61.0 released

The boost community has released their library in version 1.61.0.

boost 1.61.0 released

by the boost organization

From the release note:

Beside many bug fixes and enhancements in the existing libraries, these new libraries were added:

New Libraries

Compute:
Parallel/GPU-computing library


DLL:
Library for comfortable work with DLL and DSO. Library provides a portable across platforms way to:

  • load libraries
  • import any native functions and variables
  • make alias names for C++ mangled functions and symbols
  • query libraries for sections and exported symbols
  • self loading and self querying
  • getting program and module location by exported symbol

Hana:
A modern C++ metaprogramming library. It provides high level algorithms to manipulate heterogeneous sequences, allows writing type-level computations with a natural syntax, provides tools to introspect user-defined types and much more.

Metaparse:
A library for generating compile time parsers parsing embedded DSL code as part of the C++ compilation process. The library is similar to Spirit, however while parsers built with Spirit parse at run-time, parsers built with Metaparse parse at compile-time.