Home » Blog » Tags » basics

basics

Is C++11 uniform initialization a replacement for the old style syntax? -- Programmers.StackExchange

By Joel Lamotte | Dec 20, 2012 09:09 AM | Tags: basics

Here is a question from Programmer's StackExchange (tags [c++] and [c++11]) which most C++ developers, whatever their level, will ask as soon as they are introduced to the new Uniform Initialization syntax:

Is it recommended now to use uniform initialization in all cases? What should the general approach be for this new feature as far as coding style goes and general usage? What are some reasons to not use it?

The accepted answer clearly provides very good reasons to use this new syntax as much as possible (if your compiler supports it already): minimizing redundant typenames and avoiding the Most Vexing Parse. It also points some reasons to not use this syntax, in particular in case you're trying to call a standard container constructor.

There is one other reason not to:

std::vector<int> v{100};

What does this do? It could create a vector<int> with one hundred default-constructed items. Or it could create a vector<int> with one item whose value is 100. ... In actuality, it does the latter.

Read the full QA.

Read Stroustrup's FAQ about Uniform Initialization syntax.

Bjarne Stroustrup interview: From the Foundation and C++11, to portability and the C++ resurgence

By Blog Staff | Dec 17, 2012 09:01 AM | Tags: basics

Last Monday, Bjarne Stroustrup gave a live interview to David Intersimone of Embarcadero to kick off their CodeRage 7 conference. Bjarne discusss the new Standard C++ Foundation, the ISO C++11 standard, new language features, how C++11 builds on C++’s strengths, application portability, and C++’s ubiquitous presence in the markets.

The video is now on YouTube. Enjoy.

 

Quick Q: Why does std::map not have a const accessor? -- StackOverflow

By Blog Staff | Dec 16, 2012 12:55 PM | Tags: basics

To help balance out "introductory," "intermediate," and "advanced" content, we're trying an experiment to highlight interesting bite-sized tidbits that are in the first two categories.

Here's today's tidbit from StackOverflow's [c++11] tag:

The declaration for the [] operator on a std::map is this:

T& operator[] ( const key_type& x );

Is there a reason it isn't this?

T& operator[] ( const key_type& x );

const T& operator[] const ( const key_type& x );

Because that would be incredibly useful any time you need to access a member map in a const method.

As the two top answers show, the answer is different in C++98 and C++11, and C++11 is where it's "at" (pardon).

Read answers on StackOverflow...

Tour of C++: Second chapter posted

By Bjarne Stroustrup | Dec 2, 2012 10:25 PM | Tags: basics

This 2nd chapter of my Tour of C++ introduces the basic C++ abstraction mechanisms. If you have a 1990s view of C++, you are in for a few surprises: the integrated set of abstraction mechanisms in C++11 allows for simpler and more powerful abstractions than previously. For starters, pointers basically disappear from sight (hiding inside resource handles). Naturally, this is achieved without loss of performance. Enjoy!

Constructive comments would be most welcome.

C++11 Style: A Touch of Class -- Bjarne Stroustrup

By Blog Staff | Oct 22, 2012 07:29 PM | Tags: intermediate basics

C++11 Style: A Touch of Class -- Bjarne Stroustrup

How do we write good code in idiomatic C++11? What principles, techniques, and idioms can we exploit to make it easier to produce quality code? In this presentation, I make an argument for type-rich interfaces, compact data structures, integrated resource management and error handling, and highly-structured algorithmic code. I illustrate my ideas and guidelines with a few idiomatic code examples.

I use C++11 freely. Examples include auto, general constant expressions, uniform initialization, type aliases, type safe threading, and user-defined literals. This presentation reflects my thoughts on what "Modern C++" should mean in the 2010s: a language for programming based on light-weight abstraction with direct and efficient mapping to hardware, suitable for infrastructure code.

C++ Rvalue References Explained--Thomas Becker

By Blog Staff | Oct 14, 2012 10:21 AM | Tags: intermediate basics

What are rvalue references and move semantics, and how do they work again, exactly?

If you haven't read Thomas Becker's nice explanation (or even if you have), be sure to check it out:

C++ Rvalue References Explained

Thomas Becker

1. Introduction
2. Move Semantics
3. Rvalue References
4. Forcing Move Semantics
5. Is an Rvalue Reference an Rvalue?
6. Move Semantics and Compiler Optimizations
7. Perfect Forwarding: The Problem
8. Perfect Forwarding: The Solution
9. Rvalue References and Exceptions
10. The Case of the Implicit Move
11. Acknowledgments and Further Reading

Core C++, 4 of N: Virtual Functions -- Stephan T. Lavavej

By Blog Staff | Aug 22, 2012 07:43 PM | Tags: basics

Core C++, 4 of N: Virtual Functions -- Stephan T. Lavavej

Stephan T. Lavavej, aka STL, will take us on a journey of discovery within the exciting world of Core C++. We know lots of folks are either coming back to C++, coming to C++, or have never left C++. This lecture series, in n parts, is for all of you! Only STL can make that work (novice, intermediate, and advanced all bundled together and presented in a way only STL can do).

In part 4, Stephan teaches us about Virtual Functions. In parts 1-3, we learned about compile-time constructs. Now, we enter the realm of runtime. STL spends some time discussing inheritance and a bit about access control.

Tune in. Learn.