Linked Questions
2
votes
4
answers
2k
views
Motivation for mutable in C++ [duplicate]
Possible Duplicate:
C++ 'mutable' keyword
When have you used C++ 'mutable' keyword?
I understand what mutable means and how it is used, What I would like to know is what is the ...
- 205k
1
vote
3
answers
6k
views
Why is Mutable keyword used [duplicate]
Possible Duplicate:
C++ 'mutable' keyword
class student {
mutable int rno;
public:
student(int r) {
rno = r;
}
void getdata() const {
rno = 90;
...
- 363
0
votes
1
answer
1k
views
C++ keyword mutable [duplicate]
Possible Duplicate:
C++ ‘mutable’ keyword
What does the keyword mutable do in the following C++ code:
class X {
mutable int x;
...
};
- 1,975
363
votes
19
answers
607k
views
What is the difference between private and protected members of C++ classes?
What is the difference between private and protected members in C++ classes?
I understand from best practice conventions that variables and functions which are not called outside the class should be ...
- 40.5k
148
votes
7
answers
114k
views
const before parameter vs const after function name in C++
What is the difference between something like this
friend Circle copy(const Circle &);
and something like this
friend Circle copy(Circle&) const;
I know const after the function is used to ...
- 1,877
159
votes
9
answers
153k
views
Why is there no Constant feature in Java?
I was trying to identify the reason behind constants in Java
I have learned that Java allows us to declare constants by using final keyword.
My question is why didn't Java introduce a Constant (const)...
- 15.8k
55
votes
3
answers
25k
views
__attribute__((const)) vs __attribute__((pure)) in GNU C
What is the difference between __attribute__((const)) and __attribute__((pure)) in GNU C?
__attribute__((const)) int f() {
/* ... */
return 4;
}
vs
__attribute__((pure)) int f() {
/* ......
- 3,946
73
votes
1
answer
12k
views
C++ Lambdas: Difference between "mutable" and capture-by-reference
In C++ you can declare lambdas for example like this:
int x = 5;
auto a = [=]() mutable { ++x; std::cout << x << '\n'; };
auto b = [&]() { ++x; std::cout << x << '\...
- 38.9k
30
votes
4
answers
18k
views
C++ Difference between const positioning
I'm struggling to get my head around the differences between the various places you can put 'const' on a function declaration in c++.
What is the difference between const at the beginning:
const int ...
- 427
30
votes
5
answers
644
views
Where are the readonly/const in .NET?
In C++ you'll see void func(const T& t) everywhere. However, i havent seen anything similar in .NET. Why?
I have notice a nice amount of parameters using struct. But i see no functions with ...
user34537
21
votes
6
answers
2k
views
Is it bad practice for operator== to mutate its operands?
Scenario
I have a class which I want to be able to compare for equality. The class is large (it contains a bitmap image) and I will be comparing it multiple times, so for efficiency I'm hashing the ...
- 6,199
22
votes
1
answer
12k
views
How to use a std::lock_guard without violating const correctness?
In a subclass, I have a private std::mutex m field that I use in an implementation of a base class pure virtual method to return a value in a thread-safe way (the value can be updated by another ...
- 4,858
16
votes
4
answers
6k
views
How to make a C++ map container where the key is part of the value?
I want to store a bunch of key-value objects, but where the value object itself (and references to it) knows its key. I also want to efficiently lookup these objects given only the key.
class ...
- 29.8k
0
votes
4
answers
2k
views
Is X const &x == X & const x?
I understand that X & const x is redundant. It is not ok! But I want to know what is the difference between X const &x and X & const x?
Is the first expression saying that x is a ...
- 2,861
2
votes
5
answers
956
views
An operator == whose parameters are non-const references
I this post, I've seen this:
class MonitorObjectString: public MonitorObject {
// some other declarations
friend inline bool operator==(/*const*/ MonitorObjectString& lhs,
...
- 19.6k