Change request #1053
Remove superfluous return statements
| Status: | Rejected | Start date: | 01/04/2014 | |
|---|---|---|---|---|
| Priority: | Normal | Due date: | ||
| Assigned To: |  Deil Christoph | % Done: | 0% | |
| Category: | - | |||
| Target version: | - | |||
| Duration: |
Description
Jürgen, I’d like to re-propose a change to the Gammalib Coding and design conventions (http://gammalib.sourceforge.net/coding/index.html) that I proposed a year ago in #558 and that got lost in discussion on other things without being accepted or clearly rejected.
I propose to change “"Each function and/or method terminates with a return statement.” to “"Each function and / or method that returns something terminates with a return statement. Functions that do not return anything do not need an empty return statement at the end because returning to the caller is the default behaviour of any C / C++ / Python function / method.”
Here’s our discussion on this question from #558:
Christoph: Why require a return statement in functions / methods returning void? This seems completely superfluous (i.e. a waste of screen real estate) to me.
Jürgen: The C++ documentation says “The return statement stops execution and returns to the calling function.”, so this has nothing to do with having or having not something to return. I agree it’s optional for void functions, but personally I preferred to always have a return statement for clarity. Probably I decided to use this rule also for compatibility assurance, but this is maybe not an issue.
I don’t see how the empty return statement at the end adds clarity and I doubt there’s users with decade-old compilers that got such a fundamental C / C++ / Python behaviour wrong.
My argument for removing it is the same as before: Removing these superfluous return statements will save 1000s of lines, making more space on my screen for useful code.
Jürgen, I’m happy to make a pull request if you agree.
Recurrence
No recurrence.
History
#1
Updated by Knödlseder Jürgen over 10 years ago
It’s of course a question of style, but I also consider this as a safe guard for programmers: a function should always have a return statement.
Consider the following code:
#include<iostream>
int function(void) {
int i = 0;
}
int main(void) {
int k = function();
std::cout << k << std::endl;
}
The code is obviously wrong, yet it compiles without any warning. Running the program gives on my machine
2980, i.e. an arbitrary value.
So if you ask a programmer to always add a return statement, he would probably not forget the ones that are needed And it also shows the point where the function is intended to end.
#2
Updated by Deil Christoph over 10 years ago
But the first thing everyone learns is to compile with -Wall:
$ g++ test.cpp
$ g++-mp-4.8 -Wall test.cpp
test.cpp: In function 'int function()':
test.cpp:3:9: warning: unused variable 'i' [-Wunused-variable]
int i = 0;
^
test.cpp:4:1: warning: no return statement in function returning non-void [-Wreturn-type]
}
^
Excellent compilers warn about this by default:
$ clang++ test.cpp test.cpp:4:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ 1 warning generated.
:-)
GammaLib doesn’t have this problem and if anyone ever writes something like this CI will see it in a build with -Wall -Werror.
#3
Updated by Knödlseder Jürgen over 10 years ago
- Status changed from New to Rejected