By Adrien Hamelin | Jan 24, 2018 06:38 PM | Tags: c++17 basics
Small reminder:
C++17: Initializers for if & switch statements
by Marc Gregoire
From the article:
Two small, but very useful C++17 features are initializers for if and switch statements. These can be used to prevent polluting the enclosing scope with variables that should only be scoped to the if and switch statement. The for statement already supports such initializers since the beginning...
By Adrien Hamelin | Jan 24, 2018 06:34 PM | Tags: basics
Quick A: This is not a valid statement.
Recently on SO:
Is (4 > y > 1) a valid statement in C++? How do you evaluate it if so?
The statement (4 > y > 1) is parsed as this:
((4 > y) > 1)The comparison operators < and > evaluate left-to-right.
The 4 > y returns either 0 or 1 depending on if it's true or not.
Then the result is compared to 1.
In this case, since 0 or 1 is never more than 1, the whole statement will always return false.
By Alex Marmer | Jan 19, 2018 05:55 AM | Tags: c++14
Thiticle describes how metaprogramming can be used in a recursive lambda function.
by Alex Marmer
About the article:
Alex gives in his article several examples how lambda expressions can be used in TMP
By bfilipek | Jan 17, 2018 12:56 PM | Tags: None
In the article we describe how to limit compilation dependencies. Two methods are discussed: pimpl approach and via abstract interfaces
Pimpl vs Abstract Interface - a practical tutorial
by Bartlomiej Filipek
From the article:
In the post I covered the pimpl pattern. I discussed the basic structure, extensions, pros and cons and alternatives. Still, the post might sound a bit “theoretical”. Today I’d like to describe a practical usage of the pattern. Rather than inventing artificial names like MyClass and MyClassImpl you’ll see something more realistic: like FileCompressor or ICompressionMethod.
By bfilipek | Jan 11, 2018 03:00 PM | Tags: None
Tricky weak_ptr and shared_ptr interaction:<img alt="" data-cke-saved-src="https://2.bp.blogspot.com/-2XIQxeCUBFc/Wi2JGz_EcXI/AAAAAAAADNU/vEkN6ZtXR-Yon5YuZWBxk-6kjmHD1011ACLcBGAs/s1600/control_block.png" src="https://2.bp.blogspot.com/-2XIQxeCUBFc/Wi2JGz_EcXI/AAAAAAAADNU/vEkN6ZtXR-Yon5YuZWBxk-6kjmHD1011ACLcBGAs/s1600/control_block.png" right;"="" style="float: right; width: 230px; height: 199px;">
How a weak_ptr might prevent full memory cleanup of managed object
by Bartlomiej Filipek
From the article:
It appears that in some cases memory allocated for the object controlled by smart_ptr might not be released until all weak pointers are also ‘dead’.
By Adrien Hamelin | Jan 11, 2018 02:40 PM | Tags: intermediate
Quick A: Read the core guidelines
Recently on reddit:
() vs {} when constructing objects
If I know the type, I'll write {}. If the type is generic, I'll only write {} with zero parameters. Otherwise, I might construct an initializer_list I didn't intend to...
By Adrien Hamelin | Jan 11, 2018 02:37 PM | Tags: advanced
It needs to be used carefully, but has its uses.
C++ Comma Operator
by Ivan Sanz
From the article:
Comma operator has been with us for a long time. First seen in C spec and improved with custom overloads in C++, it quickly became one of those hidden things you shouldn’t use.
Most C/C++ books avoid speaking about goto the same way they do about comma operator. This is not fair, as both of them can be used properly on certain cases. Let’s speak about that...
By bfilipek | Jan 11, 2018 05:02 AM | Tags: c++17
Bartek's non-official year report
C++ Status at the end of 2017
by Bartlomiej Filipek
From the article:
Four things that I’d like to emphasize for the year:
- C++17 and the stable progress of the standardization
- Transparency of the Committee and compiler vendors
- Community is growing!
- More tools!
By Adrien Hamelin | Jan 10, 2018 02:48 PM | Tags: intermediate
A good sum up.
The Pimpl Pattern - what you should know
by Bartlomiej Filipek
From the article:
Have you ever used the pimpl idiom in your code? No matter what’s your answer read on
In this article I’d like to gather all the essential information regarding this dependency breaking technique. We’ll discuss the implementation (const issue, back pointer, fast impl), pros and cons, alternatives and also show examples where is it used. You’ll also see how modern C++ can change this pattern. Moreover, I hope you’ll help me and provide your examples...
By Adrien Hamelin | Jan 10, 2018 02:35 PM | Tags: intermediate c++11
How to measure time in C++?
Introduction to std::chrono
by Rachel Crawford
From the article:
How many times have you tried to call a function that alleges to return a time value only to realise you don’t know what units the value is in? Or that takes a time value as a parameter, but doesn’t specify whether the value is expected to be in milliseconds, seconds, or hours?
