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Fundamentals of Type-Dependent Code Reuse - Mark Isaacson - NDC Oslo 2015

By Mark | Feb 7, 2016 11:41 PM | Tags: advanced

From NDC Oslo 2015:

Fundamentals of Type-Dependent Code Reuse

by Mark Isaacson

About the video:

This talk surveys different code reuse problems that can be solved by leveraging type information. Mark talks about how you can optimize your algorithms so that certain types use a "fast path", all while hiding that complexity from your users. He also talks about various ways to create "opt-in" functions for your classes. The talk is accessible to novices but builds gradually to complex ideas, including a theoretical C++17 "Mixer" class that allows users to add arbitrary functions to any type, including ints, on an instance by instance granularity.

build2 — C++ Build Toolchain

By Boris Kolpackov | Feb 7, 2016 11:38 PM | Tags: repository package intermediate build

build2 is an open source, cross-platform toolchain for building and packaging C++ code. It includes a build system, package manager, and repository web interface. There is also cppget.org, a public repository of open source C++ packages.

build2 — C++ Build Toolchain

From the announcement:

This is the first alpha release and currently it is more of a technology preview rather than anything that is ready for production. It has been tested on various Linux'es, Mac OS, and FreeBSD. There is no Windows support yet (but cross-compilation is supported).

P0225: Why I want Concepts, and why I want them sooner rather than later -- Ville Voutilainen

By Blog Staff | Feb 7, 2016 09:05 AM | Tags: None

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: P0225R0

Date: 2016-02-05

Why I want Concepts, and why I want them sooner rather than later

by Ville Voutilainen

Excerpt:

This paper provides highly-opinionated statements, anecdotes and personal opinions explaining why the author thinks Concepts should go into C++17 even if no Conceptified standard library parts are included in C++17.

Raw loops vs STL algorithms

By Meeting C++ | Feb 4, 2016 10:00 AM | Tags: intermediate efficiency c++14 c++11 basics

A new post on the Meeting C++ blog, this time on <algorithm>

Raw loops vs. STL algorithms

by Jens Weller

From the article:

Since last week I am working on my CMS for static HTML pages again, and so the series about Building applications with Qt and boost continues. Today its about using STL algorithms, or how Sean Parent once said "no raw loops!". Now, I am not Sean Parent, and not event the implementers of the STL are perfect. Most code which I write is application code, which then powers Meeting C++. Also, I don't know all STL algorithms, and some times its just to tempting to write a little loop instead of searching the STL for the specific algorithm. Yesterday I had such a case.

N4573: February 2017 WG21 Meeting -- Tom Plum

By Blog Staff | Feb 2, 2016 01:09 PM | Tags: None

A new WG21 paper is available. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N4573

Date: 2016-02-02

February 2017 WG21 Meeting

by Tom Plum

Excerpt:

The February 2017 WG21 meeting is sponsored by Plum Hall and the Standard C++ Foundation. The meeting will take place at the Royal Kona Resort, in Kailua-Kona Hawaii, Monday Feb 27 to Saturday Mar 04.

Emulating C++17 Structured Bindings in C++14--John Bandela

By Adrien Hamelin | Feb 2, 2016 10:09 AM | Tags: c++14 advanced

How to use tuple return values with ease?

Emulating C++17 Structured Bindings in C++14

by John Bandela

From the article:

Bjarne Stroustrup back in Novemeber wrote a nice progress report, available here, of the Kona meeting. One of the proposals considered is called structured binding. The proposal addresses one of the inconveniences of returning multiple values from a function using tuples. While, it is very easy for a function to return multiple values, it is harder for the caller to use them. Here is an example from the write up.

consider the following function

tuple<T1,T2,T3> f() { /*...*/ return make_tuple(a,b,c); }

If we want to split the tuple into variables without specifying the type, we have to do this;

auto t = f();
auto x = get<1>(t);
auto y = get<2>(t);
auto z = get<3>(t);

The proposal puts forth the following syntax instead

auto {x,y,z} = f();               // x has type T1, y has type T2, z has type T3

I am excited for this feature, and for C++17 in general. While waiting for C++17, I decided to see how close I could get with C++14. Here is the result.

auto r = AUTO_TIE(x,y,z) = f();               // x has type T1, y has type T2, z has type T3

// Unlike the C++17 feature, you need to use r.x instead of just x
std::cout << r.x << "," << r.y << "," << r.z << "\n";

C++ User Group Meetings in February

By Meeting C++ | Feb 1, 2016 06:51 AM | Tags: user groups community

The monthly listing of upcoming C++ User Group meetings at Meeting C++:

C++ User Group Meetings in February

by Jens Weller

From the article

The monthly overview on the upcoming C++ User Group meetings! In the shortest month of the year there are still 21 C++ User Groups which are meeting!

There are 7 new C++ User Groups: Sofia, Ho Chi Minh, Iasi, Noida, Macedonia, Buenos Aires, Stuttgart / Ludwigsburg (Qt).