Questions tagged [in-class-initialization]
55 questions
6
votes
2 answers
in-class initialization of atomic
Why in this example
struct Foo {
atomic x = 1;
};
the compiler (gcc 4.8) is trying to use the atomic& operator=(const atomic&) which is deleted, (hence the example wont compile), while here
struct Bar {
Bar() { x = 1; }
atomic…
463035818_is_not_an_ai
- 109,796
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- 185
6
votes
2 answers
Unique pointer in-class initialization
Suppose I have a unique_ptr member object that I want to initialize in-class, see the code below. Why do I have to use uniform initialization (curly braces)? The second declaration spits an error, something like
so.cpp:10:31: error: expected…
vsoftco
- 55,410
- 12
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- 252
5
votes
3 answers
Order of In Class Initialization versus Constructor Initialization List
I want to initialize a bunch of members in-class to keep the source file cleaner. However, the objects take an argument I only receive via constructor and can initialize either in the constructor initialization list or in the constructor via…
ruhig brauner
- 943
- 1
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- 35
5
votes
2 answers
In-class static member initialization
Given
struct X {};
constexpr auto x = X{};
struct S {
static constexpr auto& rx = x;
};
gcc 4.8 says
error: non-constant in-class initialization invalid for static member 'S::rx'
static constexpr auto& rx = x;
…
yuri kilochek
- 12,709
- 2
- 32
- 59
5
votes
1 answer
Forward declaration, unique_ptr and in-class initializer
I have read Is std::unique_ptr required to know the full definition of T? and Forward declaration with unique_ptr?, but my question is more specific.
The following compiles:
// Compile with $ g++ -std=c++11 -c
#include
class…
ricab
- 2,697
- 4
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- 28
4
votes
1 answer
With C++, I get pointer with 0xcdcdcdcd when creating a class - what is happening?
----------------EDIT-----------------------
I was grabbing the wrong value for comparison, the cdcdcdcd was coming from somewhere else. I still have my methods throwing exceptions before they are even reached, but my problem lies elsewhere, I wish…
Steven
- 181
- 1
- 2
- 11
4
votes
1 answer
Retrieve default value of in-class initialized member
Is there any way of directly retrieving the default value of a member, which has been defined using in-class initialization? For example:
struct Test
{
int someValue = 5;
};
int main(int argc,char *argv[])
{
auto val =…
Silverlan
- 2,783
- 3
- 31
- 66
4
votes
2 answers
In class initialization and initializer list
I have recently discovered that you cant have at the same time in class initialization and initializer list.
The following code fails :
struct s
{
int i=0;
};
int main() {
s s1; //s1.i = 0
//s s2={42}; //fails
return 0;
}
If I…
Davidbrcz
- 2,335
- 18
- 27
3
votes
2 answers
In-class initialization of vector with size
struct Uct
{
std::vector vec{10};
};
The code above creates vector that contains single element with value 10. But I need to initialize the vector with size 10 instead. Just like this:
std::vector vec(10);
How can I do this with…
anton_rh
- 8,226
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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
1 answer
Class Loading vs Initialisation: Java static final variable
Example.java
public class Example {
static final int i = 10;
static int j = 20;
static {
System.out.println("Example class loaded and initialized");
}
}
Use.java
import java.util.Scanner;
public class Use {
public…
Harshit Rajput
- 83
- 1
- 9
3
votes
1 answer
Compile error with gcc when in-class initializing unique_ptr of incomplete type to nullptr
I'm writing some code using pimpl idiom with unique_ptr. When I tried to use in-class initialization to set unique_ptr to nullptr by default, gcc gave a compile error, while clang and msvc both successfully compiled the code. And if I didn't use…
X. Sun
- 315
- 3
- 15
3
votes
2 answers
In-class member initialization with an initializer list using uniform initialization syntax?
I am trying to compile the following with MSVC2013:
class SomeClass
{
struct SomeStruct { bool a,b,c; };
SomeStruct ss{false, false, false};
}
The compiler gives me the following error: SomeClass::SomeStruct::SomeStruct: no overloaded…
Dan Nestor
- 2,441
- 1
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- 45
3
votes
3 answers
Why do I need another set of braces after brace-initializing a member variable?
I was trying to use brace-initialization (which thankfully Visual Studio 2013 actually supports), but for some reason when I do it on a class, it requires two sets of braces. For example:
class NumberGrabber {
int number;
public:
…
sircodesalot
- 11,231
- 8
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- 83
2
votes
1 answer
What exactly is the in-class-initializer?
I've read many text mentioned the in-class-initializer and I've searched many question on stackoverflow, However I didn't found any precise explanation on what is the in-class-initializer. And as far as I understood the variable of build-in type…
SLN
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