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2
votes
1answer
173 views

Is it impossible to write proper, const correct callbacks in C?

In C, a non const object implicitly converts, without warning, to its const counterpart, so you can write a function, and call it as: void foo( const char *p ); char bar[] = "bar"; foo( bar ); ...
1
vote
0answers
147 views

SQL Query and Java Constant Abuse?

I am currently charged with taking over a lot of code that is written with fields names placed into Java constant at the top of the file, and then the SQL queries constructed using string ...
2
votes
1answer
114 views

Should constant values be in SHOUT_CASE when there is language support for them?

Referring primarily to here, it suggests that values which are constant in JavaScript (using the keyword const) should be named in SHOUT_CASE. I'm of the opinion though that mutability is much more ...
-1
votes
4answers
774 views

In C# Is using private constant strings better than using strings directly in the code? [closed]

Consider the following two cases: case 1: class A { private const string MyConst="Hello"; internal void CallMe() { System.Console.WriteLine(MyConst); } } Case2: class A { ...
8
votes
2answers
464 views

Const C++ DRY Strategies

For avoiding non-trivial C++ const related duplication, are there cases where const_cast would work but a private const function returning non-const wouldn't? In Scott Meyers' Effective C++ item 3, ...
0
votes
1answer
196 views

Const and non-const methods, and possible mutable data member?

I'm working on a design and implementation change due to a bug. The bug fix requires us to modify a class object in a const method. I think the two options are: Have the non-const method cast this ...
4
votes
3answers
2k views

Const means Thread-safe? [closed]

I was put onto this video: http://channel9.msdn.com/posts/C-and-Beyond-2012-Herb-Sutter-You-dont-know-blank-and-blank By http://codereview.stackexchange.com/users/39810/glampert Because I asked ...
7
votes
3answers
703 views

Passing parameters that need to be copied by value or const reference

I have a basic (mathematical) vector class, which in my opinion benefits from C++'s operator overloading. Vector-scalar operations are defined as self-modifying functions in the class itself, class ...
6
votes
4answers
570 views

Does internal state “leak” when it influences externally-visible behavior?

I have a method (in C++) which generates a value based on a parameter and the parameters from previous calls. Calling it more than once with the same parameter may generate different values each time. ...
0
votes
1answer
101 views

Is it a bad idea to use mutable for pre-allocated temporaries?

Let us assume I have the following C++ class: class MyFastMessageEncoder { public: MyFastMessageEncoder() : m_fieldEncoder(ENCODING_STYLE_DEFAULT) { } void set_encoding_style(...
0
votes
2answers
79 views

Mutable cursor in readonly object?

I've been searching for the different uses of the keyword mutable. I've found that it is generally used for caching, lazy computing, mutex, ... But I'm wondering if it is coherent to use it for a ...
13
votes
4answers
1k views

What are the problems of bringing C++-like const into a language?

I am interested in the idea of C++-like const not that particular execution (like casting away const). Take for example C# -- it lacks C++-like const, and the reason for it is the the usual -- people ...
2
votes
1answer
608 views

Are there advantages to declaring stack variables constant in C++

It's not clear to me what benefits there are of declaring your stack variables as constant in C++, I was hoping somebody might explain the benefits and purpose for this technique. For example: void ...
3
votes
1answer
580 views

Which is better to use? (Enum or Constant)

I have my enum like this. enum Size{PAGE_SIZE=20, HEADER_SIZE=30 }; I only use them as constants(No enum variable created) in my program. i.e= int x = PAGE_SIZE + 20; So what is the ...
24
votes
4answers
6k views

When and for what purposes should the const keyword be used in C for variables?

While getting my code reviewed here the issue of using the const keyword came up. I understand that it is used for implementing read-only behaviour on variables. I am confused about what are the ...
1
vote
1answer
174 views

Implementation defined behaviour changing const type in c

The C standard states that if an attempt is made to change a const type,the result is implementation defined.This gives error on my system,but what does it depend on(compiler,os)? What are the ...
2
votes
2answers
534 views

In C# what is lifetime or lifespan of constant variable?

In C# if i declare a constant variable is any memory allocated to it as it acts as a compile time replacement? How long is the variable's life?
3
votes
4answers
3k views

Immutable Method in Java

In Java, there is the final keyword in lieu of the const keyword in C and C++. In the latter languages there are mutable and immutable methods such as stated in the answer by Johannes Schaub - litb ...
2
votes
1answer
70 views

Reading data from file and const

Is it sane to let a read method on a file object to be const? For example size_t read(void* buffer,size_t length) const; The read method does not change the contents of the file, but updates the ...
9
votes
5answers
825 views

Zero as a constant?

I have come across this programming idiom recently: const float Zero = 0.0; which is then used in comparisons: if (x > Zero) {..} Can anyone explain if this is really any more efficient or ...
7
votes
2answers
4k views

Do people use const a lot when programming in Objective C?

Related: “sending 'const NSString *' to parameter of type 'NSString *' discards qualifiers” warning Sometimes, I think it's useful though. I may need to pass an a table and want to make sure that the ...
17
votes
7answers
13k views

Difference between immutable and const

I've often seen the terms immutable and const used interchangeably. However, from my (little) experience, the two differ a lot in the 'contract' they make in code: Immutable makes the contract that ...