Range Concepts, Part 2 of 4: Infinite Ranges

By Meeting C++ | Feb 20, 2014 06:54 AM | Tags: ranges intermediate experimental c++11 boost advanced

The second part of Eric Nieblers Series about ranges:

Range Concepts, Part 2 of 4: Infinite Ranges

By Eric Niebler

From the Article:

In the last post, I tried to make delimited ranges fit into the STL and found the result unsatisfying. This time around I’ll be trying the same thing with infinite ranges and will sadly be reaching the same conclusion. But the exercise will point the way toward an uber-Range concept that will subsume delimited ranges, infinite ranges, and STL-ish pair-o’-iterator ranges.

Range Concepts, Part 1 of 4: Delimited Ranges

By Meeting C++ | Feb 17, 2014 01:02 PM | Tags: ranges intermediate experimental efficiency advanced

The start on a series about ranges from Eric Niebler:

Range Concepts, Part 1 of 4: Delimited Ranges

By Eric Niebler

From the Article:

I’ve been digging into ranges recently, and I’m finding them to be more than just a pair of iterators. In a series of posts, I’ll be expanding the notion of what a range is to cover some kinds of ranges not easily or efficiently expressible within the STL today: delimited ranges and infinite ranges. This post deals with the problems of representing delimited ranges with STL iterators.

Find the Bug -- Andrzej Krzemieński

By Blog Staff | Feb 13, 2014 12:17 PM | Tags: intermediate

Can you spot the bug?

Find the Bug

by Andrzej Krzemieński

From the article:

Today, let's take a short test. Find what is likely to be a bug in the following code and suggest how to fix it.

void Catalogue::populate(vector<string> const& names)
{
  vec_.clear();
  vec_.resize(names.size());

  for (size_t i = 0; i < names.size(); ++i)
    vec_[i] = make_unique<Entry>(names[i]);
}

C++ Papers for Issaquah - Library, Graphics, Networking, Numerics and Undefined Behavior

By Meeting C++ | Feb 12, 2014 12:51 PM | Tags: undefined behavior standardization numerics networking library issaquah intermediate graphics experimental c++14 advanced

This is the last part in the series for Issaquah, and its the most diverse:

C++ Papers for Issaquah - Library, Graphics, Networking, Numerics & Undefined Behavior

by Jens Weller

From the Article:

The 4th and last part about the C++ Papers for Issaquah. I already covered the first batch of proposals from the Library subgroup in the previous part, now its all about papers from Library, Graphics, Networking, Numerics and Undefined Behavior. A very diverse part.

C++ Papers for Issaquah - Library I

By Meeting C++ | Feb 11, 2014 03:58 AM | Tags: standardization issaquah intermediate experimental c++14 advanced

The third part of my series about the papers for Issaquah is about the first batch of library proposals

C++ Papers for Issaquah - Library I

by Jens Weller

From the article:

The 3rd part of the C++ papers for Issaquah series will be about the library proposals. The last part covered the papers from concepts, database and evolution. There are a lot of proposals from the library group, and I think some of them are the most interesting, as they don't have any impact on the core language.

Quick Q: What's the difference between std::merge and std::inplace_merge? -- StackOverflow

By Blog Staff | Feb 7, 2014 10:47 AM | Tags: None

Quick A: "Inplace" can deal with overlapping ranges, but will take either more space or more time.

Today on StackOverflow:

Difference between std::merge and std::inplace_merge?

What is the difference between std::merge and std::inplace_merge in terms of complexity and result when it is executed on two consecutive ranges with elements that are all different ? (I am not a native english speaker and I am not sure to clearly understand what "inplace" means)

Overload 119 is now available

By Blog Staff | Feb 7, 2014 09:36 AM | Tags: intermediate

Overload 119 is now available. It contains the following C++-related articles, and more:

Overload 119

Feature: Static Polymorphic Named Parameters in C++ -- Martin Moene

Adding parameters to an object can be messy. Here is a description of method chaining -- an interesting way to pass parameters into methods in a more readable fashion.

Capturing Lvalue References in C++11 Lambdas -- Pete Barber

How confusing does it get when references refer to references and references are captured by value? Pete Barber shows us that it all falls out in the C++ consistency wash.

C++ Papers for Issaquah - Concepts, Database and Evolution

By Meeting C++ | Feb 6, 2014 04:33 PM | Tags: standardization issaquah intermediate experimental evolution database concepts advanced

This is the second part of my series about the papers for the next C++ committee meeting in Issaquah:

C++ Papers for Issaquah - Concepts, Database & Evolution

by Jens Weller

From the article:

This is the second part about the papers for the C++ committee meeting in February in Issaquah. This time featuring papers from the subgroups of concept, database and evolution. Again, most papers in this series aim for a standard after C++14, most important for C++14 will be the national comments on the new standard. Also there are no new papers from the core working group, only the active issues, defects report and closed issues report are on this mailing.

Quick Q: Why does unique_ptr take two template parameters when shared_ptr only takes one? -- SO

By Blog Staff | Feb 6, 2014 05:39 AM | Tags: None

Recently on StackOverflow:

Why does unique_ptr take two template parameters when shared_ptr only takes one?

Both unique_ptr and shared_ptr accept a custom destructor to call on the object they own. But in the case of unique_ptr, the destructor is passed as a template parameter of the class, wherease the type of shared_ptr's custom destructor is to be specified as a template parameter of the constructor.

template <class T, class D = default_delete<T>>
class unique_ptr
{
    unique_ptr(T*, D&); //simplified
    ...
};

and

template<class T>
class shared_ptr
{
    template<typename D>
    shared_ptr(T*, D); //simplified
    ...
};

I can’t see why such difference. What requires that?

Quick Q: What do braces mean as a function argument? -- StackOverflow

By Blog Staff | Feb 5, 2014 03:12 AM | Tags: basics

Quick A: Something cool and convenient -- you can construct a temporary variable of the parameter type without having to repeat the type.

From SO:

C++ 11 Curly Braces

I haven't used C++ for a good few years, and have just come across this:

program.build({ default_device })

The definition is:

cl_int build(
    const VECTOR_CLASS<Device>& devices,
    const char* options = NULL,
    void (CL_CALLBACK * notifyFptr)(cl_program, void *) = NULL,
    void* data = NULL) const

What are the curly braces there for? I have never seen them used in a function call like this before. I assume it has something to do with the function pointer, but that seems optional?