A mutable can be modified after it is created.
A mutable can be modified after it is created. It is a keyword in functional programming opposite to immutable.
Related tags:
Questions tagged [mutable]
1184 questions
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votes
1 answer
Swift set or update asset in core data
Two Entities
Gymnast is one to many to Meet
I would like to when I save a new meet, it gets assigned to as a meet to each gymnast where they can then score their individuals scores for each event
Maybe I completely wrong in my logic, but here is…
debratton
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votes
3 answers
Mutable local variable in C++
When I try to create a mutable local variable in C++ I get:
error mutable is not allowed
during compilation with Visual Studio.
does C++ have a some kind of Mutable local variable?
is there a better way then const_cost for defining a "non const"…
Aviv A.
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votes
1 answer
'Mutating method sent to immutable object error' in Xcode
I am unsure why I get this error when I run my program a certain way.
2014-05-15 16:19:28.932 Puzzle[1002:f803] *** WebKit discarded an uncaught exception in the webView:shouldInsertText:replacingDOMRange:givenAction: delegate:…
user1633930
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2 answers
why does this happen with lists in python
When I assign one list to another, I see that upon changing one of the elements in one list, the other element is automatically assigned with that value.
What is the reason for this behavior?
>>> a = [1,2,3] # create a list
>>> b = a
>>> b
[1, 2,…
user2927392
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votes
1 answer
Condition for creating a immutable class?
To make a immutable class , Effective Java has one last condition.
To make a class immutable, follow these five rules:
5- Ensure exclusive access to any mutable components. If your class has any fields that refer to mutable objects, ensure that…
Thinker
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votes
1 answer
immutable to mutable
How do I wrap an immutable class in a mutable one?
For example wrapping Integer and String and create MutableInteger and MutableString.
It seems that there are various ways available for doing this. I want to do this with less effort on coding side…
MBZ
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votes
1 answer
Is it possible to write dirty flags with ref getters?
Is it possible to write dirty flags with ref returned get only properties in C#?
public class ByRef where T : struct
{
private bool _dirty;
private T _value;
public ref T Value
{
get
…
Shadowblitz16
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votes
1 answer
strange way of working in DFS in one of leetcode questions
I think this is just about some fundamental difference about Python function and data structure but I wasn't able to figure out why the method II doesn't working it seems the variable res also change values during the traverse but just not as…
xappppp
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votes
1 answer
Some puzzles about python mutability and immutablity
I'm confused about the following 3 codes.
1.The first one is intuitive for me util I saw (B):
(A)
def change (mylist):
mylist[0] = 33
mylist[1] = 44
mylist[2] = 55
print("inside the function",mylist)
alist =…
PeterHsieh
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votes
4 answers
C++ unordered_map::insert won't compile
I just need a hash map from one float to another. Should be simple, shouldn't it? Compiler just won't accept it:
Declaration:
unordered_map m_mffPhotoPeakMap;
Use:
float CProductSpecs::AddToMap(float fEnergy, float returnedValue)…
UserX
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votes
1 answer
Accidentally mutating a copy of a struct instead of the struct itself
Having programmed with identity types for years, I find mutating value types very stressful to use due to the constant risk of accidentally assigning (and thus copying) to a new variable and then mutating that copy and expecting to see those changes…
pseudosudo
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votes
2 answers
Python 2.7 - clean syntax for lvalue modification
It is very common to have struct-like types that are not expected to be modified by distant copyholders.
A string is a basic example, but that's an easy case because it's excusably immutable -- Python is unusual in even allowing things like method…
personal_cloud
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votes
1 answer
Iterate all inner NSDictionary items and change them?
In my particular case I have NSDictionary object which can contain NSString objects as keys and NSString and NSDictionary objects as values. The inner dictionaries can also contain NSDictionary objects.
What if I need to iterate all the inner…
Vyachaslav Gerchicov
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votes
1 answer
How to avoid mutable in this case
Consider this:
struct Foo {
std::vector x;
mutable double* xp;
void foo () const { xp = &(x[0]); }
};
This wont compile with because of
error: invalid conversion from 'const double*' to 'double*' [-fpermissive]
The fix is…
463035818_is_not_an_ai
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votes
5 answers
Creating a Mutable string class in python
I am trying to create a class in python that will have all the str characteristics , but will also be mutable.
Example:
>>> a = mutableString("My string")
>>> print a +"c"
"My stringc"
>>> a[0] = "a"
>>> a
"ay string"
How is it possible by…
yehiel mashraki
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