Question What C++ idioms should C++ programmers know? By C++ idioms, I mean design patterns or way of doing certain things that are only applicable for C++ or more applicable for C++ than most other languages. Edit: Please explain why one should use the idioms and what the idioms do. ...
Right now I'm using the following to minimize boxed object creation: String myString = "" + myChar; Is this the idiomatic way to do it? (IMHO it feels a little awkward.) ...
I'm working on a Chart class and it has a margin parameter, that holds :top, :bottom, :right and :left values. My first option was to make margin a setter and set values like this: # Sets :left and :right margins and doesn't alter :top and :bottom chart.margins = {:left => 10, :right => 15} It's nice, because it is clearly a setter, ...
I find myself using PHP-like loops a lot in Ruby and it feels wrong when the rest of the language is so neat. I wind up with code like this: conditions_string = '' zips.each_with_index do |zip, i| conditions_string << ' OR ' if i > 0 conditions_string << "npa = ?" end # Now I can do something with conditions string I feel like I...
There's a less common C++ idiom that I've used to good effect a few times in the past. I just can't seem to remember if it has a generally used name to describe it. It's somewhat related to mixins, CRTP and type-erasure, but is not specifically any of those things. The problem is found when you want to add some implementation to a clas...
heya, I'm just wondering, is there a Python idiom to check if a string is empty, and then print a default if it's is? (The context is Django, for the __unicode__(self) function for UserProfile - basically, I want to print the first name and last name, if it exists, and then the username if they don't both exist). Cheers, Victor ...
From http://jaynes.colorado.edu/PythonIdioms.html "Build strings as a list and use ''.join at the end. join is a string method called on the separator, not the list. Calling it from the empty string concatenates the pieces with no separator, which is a Python quirk and rather surprising at first. This is important: stri...
Is there a more concise and idiomatic way to write the following code, which is used to specify default values for optional parameters (in the params/options hash) to a method? def initialize(params={}) if params.has_key? :verbose @verbose = params[:verbose] else @verbose = true # this is the default value end end I wou...
How to implement Named Parameter idiom in Java? (especially for constructors) I am looking for an Objective-C like syntax and not like the one used in JavaBeans. A small code example would be fine. Thanks. ...
In the context of programming, how do idioms differ from patterns? I use the terms interchangeably and normally follow the most popular way I've heard something called, or the way it was called most recently in the current conversation, e.g. "the copy-swap idiom" and "singleton pattern". The best difference I can come up with is code w...
I'm finding myself writing this bit of code in my controllers a lot: params[:task][:completed_at] = Time.parse(params[:task][:completed_at]) if params[:task][:completed_at] Don't get hung up on what I'm doing here specifically, because the reasons change every time; but there are many circumstances where I need to check for a value in...
I remember seeing somewhere a dictionary of idiomatic word pairs for use in programming. Like get-set, open-close, allocate-free and so on. Does anyone remember an URL? ...
I just came across this post and found a very elegant way of initializing maps http://stackoverflow.com/questions/138600/initializing-a-static-stdmapint-int-in-c/1730798#1730798 So i wanted to start a thread in which we can list such idioms. They surely make you appreciate the power and expressiveness of C++ ...
I have just read Python Cookbook. The book is amazing. I think the best use of this book is that it provides lots of examples that show python in real problem applications. Many of the idioms include metaprogramming techniques. I wonder if there is any catalog that summarizes metaprogramming idioms in Python? Python Cookbook is very ...
What is the most pythonic way to read in a named file, strip lines that are either empty, contain only spaces, or have # as a first character, and then process remaining lines? Assume it all fits easily in memory. Note: it's not tough to do this -- what I'm asking is for the most pythonic way. I've been writing a lot of Ruby and Java ...
I have 30 runs of data, each stored in a separate CSV file, runi.csv, i = 0:29. Let's say I want to collect them all into a list. Best way I know how to do this is runs = list() for (i in 1:30) { runs[[i]] = read.csv(paste("run", i-1, ".csv")); } Now let's further say that each of these data frames stored in the list has the same co...
For this class definition: type Foo(f1: int, f2: string) = member x.F1 = f1 member x.F2 = PostProcess f2 Will PostProcess (some string manipulation function) gets called every time f2 is accessed? If the answer is yes and I want to avoid it, what’s the right idiom? Is this one below recommended? It is a bit too verbose for me. type F...
Is there a common idiom for avoiding pointless slice copying for cases like this: >>> a = bytearray(b'hello') >>> b = bytearray(b'goodbye, cruel world.') >>> a.extend(b[14:20]) >>> a bytearray(b'hello world') It seems to me that there is an unnecessary copy happening when the b[14:20] slice is created. Rather than create a new slice i...
In C++, I often needed NVI to get consistency in my APIs. I don't see it used as much among others in C#, though. I wonder if that is because C#, as a language, offers features that makes NVI unnecessary? (I still use NVI in C#, though, where needed.) ...
Note: marked as community wiki. In recent days, I've realized how little I know about C++. Besides: using the STL implementing RAII implementing ref-counted smart pointers writing my own policy-based template classes overloading operators << for fun What other techniques are must-know for a good C++ programmer? Thanks! ...