This is the initialization performed when a variable is constructed with no initializer.
Questions tagged [default-initialization]
11 questions
7
votes
1 answer
Ambiguity between default-initialization and value-initialization
I found many articles explaining the difference between "default-initialization and value-initialization" but in fact I didn't understand clearly.
Here's an example:
class A{
public:
int x;
};
int main(){
A a;// default initialization…
Rami Yen
- 165
- 1
- 6
6
votes
6 answers
How to let a variable be dependent on other variables inside a class?
What is wrong with the variable international_standard_book_number? How can I make it that it changes, whenever isbn_field_i changes?
#include
#include
class ISBN
{
private:
unsigned int isbn_field_1 = 0;
unsigned int…
SAJW
- 235
- 2
- 10
5
votes
1 answer
Is the Order of Array Element Default-Initialization Defined?
When an array is default initialized,
is the order in which it's elements are default initialized defined by the C++ standard?
To give an example, is the following C++ program guaranteed do print strictly ascending memory addresses?
#include…
ChrisB
- 1,540
- 6
- 20
4
votes
2 answers
Safely initializing a std::array of bools
Given this array declaration and initialization:
std::array invalid_params{};
Can I assume that all the elements in the array will always be initialized to false, or is it better to do it explicitly?
anastaciu
- 23,467
- 7
- 28
- 53
3
votes
0 answers
default initialization, value initialization and in-class-initialization of object not getting properly?
You might feel code is long and I write lot of things but believe me it is quite simple.
I referred these two answers on stack-overflow for understanding this.
post1 & post2
Code
#include
class A
{
public:
int…
Abhishek Mane
- 619
- 7
- 20
3
votes
2 answers
Why do designated initializers zero-initialize the data members?
Below is from cppref of Designated initializers:
struct A { int x; int y; int z; };
A b{.x = 1, .z = 2}; // ok, b.y initialized to 0
By default, all fundamental types are default-initialized rather than zero-initialized in C++.
Why do designated…
xmllmx
- 39,765
- 26
- 162
- 323
2
votes
0 answers
Lifetime extension of default initialized const ref& in an aggregate
I know that binding prvalues to const ref variables will extend the lifetime of the temporary. Now I thought I'd be clever to have a struct options that contains a const ref field B_options (which is used for initializing a subclass in my context).…
glades
- 3,778
- 1
- 12
- 34
2
votes
1 answer
Why member of class type needs initialization?
I am reading about constructors in C++. I came across this example:
#include
using namespace std;
class NoDefault
{
public:
NoDefault(const std::string&);
};
struct A
{
NoDefault my_mem;
};
int main()
{
A a;
…
Aadil Hoda
- 592
- 7
- 17
0
votes
1 answer
Initializing an array of objects created on the heap
Given the non trivial data structure:
claas MyClass
{
public:
MyClass():x(0), p(nullptr)
{}
private:
int x;
int* p;
};
Is there any guarantee provided by the c++ specification that the default constructor will be called for each instance…
Sampath
- 1,144
- 1
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- 38
0
votes
1 answer
c++11 - zero-initi of members insted of default-init
In the below code, I expect members of a being inited with gargabe as they are not mentioned in the members-init-list of the called constructor (with two int parameters). Instead, I'm constantly getting 0 in both i and j of a, b and c and I am…
Anton Tretyakov
- 303
- 1
- 9
0
votes
1 answer
question about default initialization in c
I am studying for an interview and found this question a bit bewildering. Would appreciate your advice.
What is not initialized by default?
The last variable of a static array in which the first variables are explicitly initialized in a…
jrz
- 1,213
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- 54