Anyone can learn how to code, but when one gets stuck on a certain problem that they encountered, can anyone just ask the experts on how to solve it? Of course, but depending on how one asks a question, or even why one is asking it, can ultimately determine the kind of responses that follow. For example, several times in the past I have been stumped on a part of my code and why it was wrong, but instead of trying to understand the error in my code with the resources I have online, I simply copy and paste chunks of it to boards and hope someone solves it overnight. Of course I learned after that not only was it lazy of me to do so, it was flat out the incorrect and often rule-breaking way of asking questions.
Thus, it is important to do things the smart way, and that is to think of a clear and concise question, and try and look for answers using other sources before going on online boards. Most of the time, answers can be found through a simple search, while other people have asked the same questions that lead to given solutions. But in the case that all other resources have been exhausted, that would be the time to directly consult the community. Approaching the community is a careful matter, however. Software engineers need to get most out of the information in order to get more knowledge, and to get better information is by asking better, or smarter questions.
StackOverflow is open to everyone, and is a great tool for getting great answers. However, as everyone can use it, there can also be poor questions that can lead to poor answers, such as misleading or irrelevant solutions, and even as poor as having questions as answers. This is why it is important to ask questions in a smart way, such as showing knowledge of what one is doing and how things work, either from their own experience or from what they have learned when searching for answers elsewhere. A great example is shown below, in which the inquirer showcases what he has learned from the manual, and also how he would try and answer the question.
Q: Is sizeof(void()) a legal expression?
From [5.3.3/1], I found that:
The sizeof operator shall not be applied to an expression that has function or incomplete type
From [3.9/5] I found that:
Incompletely-defined object types and cv void are incomplete types
Anyway, for sizeof does not evaluate it's operands, I would have said that sizeof(void()) was a
legal expression (actually GCC compiles it and the result is 1).
On the other side, from here, void is not mentioned while discussing sizeof, neither when the
types having size 1 are mentioned, nor in the list of the ones having an implementation defined size.
The question is thus: is sizeof(void()) a legal expression?
Is it guaranteed to have size equal to 1?
Or is it a legal expression resulting in an UB and that's all?
The inquirer already gives additional information from online documentation as to why his answer would be wrong, thus giving any potential helpers an insight to his/her thinking process. Apart from the main question, he/she offers two other questions that could help clarify what kind of solution is being sought. As a result of this smart and informative question, five answers were given, one of which is shown below.
A little premise.
The question arose from a misinterpretation of the sizeof operator.
In fact the OP considered void() an expression that has incomplete type in the context of sizeof and the
question itself can be read as - why sizeof accept the expression void(), that is an incomplete type and
should not be accepted as mentioned in the working draft?
That's why [3.9/5] is mentioned actually, otherwise it wouldn't have made sense.
That said, the fact is that the question contains actually two interesting questions:
Why does sizeof(void()) is not legal?
This is the actual question as from the title itself.
Why does sizeof((void())) is not legal?
This is the intended question of the OP.
Answers below:
void() in sizeof(void()) is interpreted as an expression that as function type and it is ill-formed as for
[5.3.3/1] (emphasis mine):
The sizeof operator shall not be applied to an expression that has function or incomplete type
(void()) in sizeof((void())) is an expression that has incomplete type void (note that sizeof is an unevaluated
context) and it is ill-formed as for [5.3.3/1] (emphasis mine):
The sizeof operator shall not be applied to an expression that has function or incomplete type
In both cases GCC compiles the code with a warning.
The first is a simple explanation of the function type in question. Other answers referred to documentations, and others gave specific examples. All in all, this question succeeded in finding appropriate and relevant answers.
Not smart questions are often done with little to no thought process, creating the opposite result of what smart questions can put out. Shown below is an example of a question where the inquirer is asking how to create an Android application with Phonegap using Eclipse.
Q: How to create Android Application with Phonegap?
How to Installing and configuring PhoneGap for Android mobile development
with Eclipse. can i get sample phonegap projects with android.
pls provide Phonegap tutorial or pdf files.
Just as the question took little to no effort to make, likewise the answer was as simple as giving a link to the Phonegap website stating that everything the inquirer needs is there. Instead of asking for tutorials and sample projects, the inquirer should research more about Phonegap and possibly a beginner’s guide to Android mobile development. Knowing more about the subject may lead to more specific questions that would benefit them.
As Eric Steven Raymond likes to say, hackers like hard-hitting problems and well thought-out questions. They would be very descriptive and informative when solving the problems as they too would like to make it clear for themselves. This applies to smart software engineers too. Asking smart questions is a great way to gather fellow software engineers to brainstorm various solutions and answers. It may also potentially give the opportunity of interacting with people sharing similar interests. However, asking not smart questions will most likely yield lackluster results, such as links to complicated text that even beginners might not even understand. Overall, it is important to keep in mind that smart questions lead to good responses.