Articles & Books

C++17: I See a Monad in Your Future!

Thoughts on Monads and Futures in C++

C++17: I See a Monad in Your Future!

by Bartosz Milewski

From the Article:

If you thought you were safe from functional programming in your cozy C++ niche, think again! First the lambdas and function objects and now the monad camouflaged as std::future. But do not despair, it’s all just patterns. You won’t find them in the Gang of Four book, but once you see them, they will become obvious.

Range Concepts, Part 3 of 4: Introducing Iterables

The third part of Eric Nieblers Series on ranges

Range Concepts, Part 3 of 4: Introducing Iterables

by Eric Niebler

From the Article:

In the last two blog posts, I describes the challenges I’ve encountered while building a next-generation range library. In this post, I’ll sketch for you my proposed solution: refinements of the range concepts that allow delimited, infinite, and pair-o’-iterator-style ranges to fit comfortably within the concept hierarchy without loss of performance or expressive power and with increased safety. I’ve built a range library around these concepts that subsumes and extends all of the C++98 STL algorithms and the Boost.Range adaptors, so I can say with confidence that these concepts lead to a useful and consistent generic range library.

Quick Q: How can I make my constructor take a list of things, like map and vector? -- StackOverflow

Quick A: By having your constructor take an initializer_list<> of the appropriate type.

Today on StackOverflow:

Constructor similar to std::map or std::vector in a class

I'm creating a class and I want to know how to create a constructor similar to the std::map or std::vector style.

std::map<std::string, std::string> map = {
    {"foo", "bar"},
    {"biz", "buz"},
    {"bez", "boz"}
};

The difference is that I don't want my class to ask for types that wants to accept, just like std::map does.

std::map<std::string, std::string>

I want my class to accept that style of arguments:

{
    {"foo", "bar"},
    {"biz", "buz"},
    {"bez", "boz"}
};

But with defined type. (std::string, Typer)

The 'Typer' is a class that I will insert as value on the std::map.

Thank you.

Clang 3.4 and C++14

With the technical completion of C++14 (we think) reported on Monday, we'd like to link to this recent post for your Friday reading pleasure to recap some of the features of C++14.

There are other articles summarizing C++14 features, but some of the short code examples in this one go beyond what we've seen posted elsewhere and are quite interesting. For example, check out primes.

Clang 3.4 and C++14

by Scott Prager

From the article:

With each new release, gcc and clang add on more C++11 and C++14 features. While clang has been behind on some features, though ahead on others, they now claim to have C++1y all worked out...

Range Concepts, Part 2 of 4: Infinite Ranges

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

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

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]);
}