Avoid calling move constructor
up vote
9
down vote
favorite
I have following example
#include <cstdint>
class FooC
{
public:
FooC(uint16_t iPort, uint16_t iPin)
: PORT(iPort)
, PIN(iPin)
{
};
~FooC() = default;
FooC() = delete;
FooC(const FooC&) = delete;
FooC(FooC&&) = delete;
private:
const uint16_t PORT;
const uint16_t PIN;
};
int main()
{
FooC array[2] = {
FooC(1,2),
FooC(3,4)
};
}
and I don't want to call the default, move and copy constructor. Due to that I deleted the functions. Unfortunately this results in following error (compiled with C++11)
: In function 'int main()':
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
Compiler returned: 1
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
c++ c++11 c++17
add a comment |
up vote
9
down vote
favorite
I have following example
#include <cstdint>
class FooC
{
public:
FooC(uint16_t iPort, uint16_t iPin)
: PORT(iPort)
, PIN(iPin)
{
};
~FooC() = default;
FooC() = delete;
FooC(const FooC&) = delete;
FooC(FooC&&) = delete;
private:
const uint16_t PORT;
const uint16_t PIN;
};
int main()
{
FooC array[2] = {
FooC(1,2),
FooC(3,4)
};
}
and I don't want to call the default, move and copy constructor. Due to that I deleted the functions. Unfortunately this results in following error (compiled with C++11)
: In function 'int main()':
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
Compiler returned: 1
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
c++ c++11 c++17
5
use C++17 :-)...
– marcinj
yesterday
1
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
2
Have you tried removing the=
– JVApen
yesterday
1
Andconstexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday
add a comment |
up vote
9
down vote
favorite
up vote
9
down vote
favorite
I have following example
#include <cstdint>
class FooC
{
public:
FooC(uint16_t iPort, uint16_t iPin)
: PORT(iPort)
, PIN(iPin)
{
};
~FooC() = default;
FooC() = delete;
FooC(const FooC&) = delete;
FooC(FooC&&) = delete;
private:
const uint16_t PORT;
const uint16_t PIN;
};
int main()
{
FooC array[2] = {
FooC(1,2),
FooC(3,4)
};
}
and I don't want to call the default, move and copy constructor. Due to that I deleted the functions. Unfortunately this results in following error (compiled with C++11)
: In function 'int main()':
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
Compiler returned: 1
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
c++ c++11 c++17
I have following example
#include <cstdint>
class FooC
{
public:
FooC(uint16_t iPort, uint16_t iPin)
: PORT(iPort)
, PIN(iPin)
{
};
~FooC() = default;
FooC() = delete;
FooC(const FooC&) = delete;
FooC(FooC&&) = delete;
private:
const uint16_t PORT;
const uint16_t PIN;
};
int main()
{
FooC array[2] = {
FooC(1,2),
FooC(3,4)
};
}
and I don't want to call the default, move and copy constructor. Due to that I deleted the functions. Unfortunately this results in following error (compiled with C++11)
: In function 'int main()':
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
:28:5: error: use of deleted function 'FooC::FooC(FooC&&)'
};
^
:16:4: note: declared here
FooC(FooC&&) = delete;
^~~~
Compiler returned: 1
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
c++ c++11 c++17
c++ c++11 c++17
asked yesterday
Zlatan
1308
1308
5
use C++17 :-)...
– marcinj
yesterday
1
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
2
Have you tried removing the=
– JVApen
yesterday
1
Andconstexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday
add a comment |
5
use C++17 :-)...
– marcinj
yesterday
1
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
2
Have you tried removing the=
– JVApen
yesterday
1
Andconstexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday
5
5
use C++17 :-)...
– marcinj
yesterday
use C++17 :-)...
– marcinj
yesterday
1
1
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
2
2
Have you tried removing the
=
– JVApen
yesterday
Have you tried removing the
=
– JVApen
yesterday
1
1
And
constexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
And
constexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday
add a comment |
2 Answers
2
active
oldest
votes
up vote
13
down vote
In C++11 and C++14, you can use nested braces:
FooC array[2] = {{1,2}, {3,4}};
In C++17 your code should already work as written thanks to the new prvalue/materialization rules ("guaranteed copy elision").
1
C++17 demo
– Kerrek SB
yesterday
add a comment |
up vote
4
down vote
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
No with your current syntax (before C++17) and yes (in C++17).
Pre-C++17:
This is not possible. The aggregate initialization copies the initializers into the aggregate. This means you have to have an accessible copy/move constructor. In C++11 you have to pass the constructor parameters as their own braced-init-list. This means you aren't copying FooC
's but instead copy-list-initializing the FooC
's in the array which calls the 2 parameter constructor instead of the copy/move constructor.
FooC array[2] = {
{1, 2},
{3, 4}
};
C++17:
You no longer have temporary objects in the braced-init-list and each element of the array will be directly initialized instead of copy initialized.
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
13
down vote
In C++11 and C++14, you can use nested braces:
FooC array[2] = {{1,2}, {3,4}};
In C++17 your code should already work as written thanks to the new prvalue/materialization rules ("guaranteed copy elision").
1
C++17 demo
– Kerrek SB
yesterday
add a comment |
up vote
13
down vote
In C++11 and C++14, you can use nested braces:
FooC array[2] = {{1,2}, {3,4}};
In C++17 your code should already work as written thanks to the new prvalue/materialization rules ("guaranteed copy elision").
1
C++17 demo
– Kerrek SB
yesterday
add a comment |
up vote
13
down vote
up vote
13
down vote
In C++11 and C++14, you can use nested braces:
FooC array[2] = {{1,2}, {3,4}};
In C++17 your code should already work as written thanks to the new prvalue/materialization rules ("guaranteed copy elision").
In C++11 and C++14, you can use nested braces:
FooC array[2] = {{1,2}, {3,4}};
In C++17 your code should already work as written thanks to the new prvalue/materialization rules ("guaranteed copy elision").
answered yesterday
Kerrek SB
359k60673909
359k60673909
1
C++17 demo
– Kerrek SB
yesterday
add a comment |
1
C++17 demo
– Kerrek SB
yesterday
1
1
C++17 demo
– Kerrek SB
yesterday
C++17 demo
– Kerrek SB
yesterday
add a comment |
up vote
4
down vote
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
No with your current syntax (before C++17) and yes (in C++17).
Pre-C++17:
This is not possible. The aggregate initialization copies the initializers into the aggregate. This means you have to have an accessible copy/move constructor. In C++11 you have to pass the constructor parameters as their own braced-init-list. This means you aren't copying FooC
's but instead copy-list-initializing the FooC
's in the array which calls the 2 parameter constructor instead of the copy/move constructor.
FooC array[2] = {
{1, 2},
{3, 4}
};
C++17:
You no longer have temporary objects in the braced-init-list and each element of the array will be directly initialized instead of copy initialized.
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
add a comment |
up vote
4
down vote
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
No with your current syntax (before C++17) and yes (in C++17).
Pre-C++17:
This is not possible. The aggregate initialization copies the initializers into the aggregate. This means you have to have an accessible copy/move constructor. In C++11 you have to pass the constructor parameters as their own braced-init-list. This means you aren't copying FooC
's but instead copy-list-initializing the FooC
's in the array which calls the 2 parameter constructor instead of the copy/move constructor.
FooC array[2] = {
{1, 2},
{3, 4}
};
C++17:
You no longer have temporary objects in the braced-init-list and each element of the array will be directly initialized instead of copy initialized.
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
add a comment |
up vote
4
down vote
up vote
4
down vote
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
No with your current syntax (before C++17) and yes (in C++17).
Pre-C++17:
This is not possible. The aggregate initialization copies the initializers into the aggregate. This means you have to have an accessible copy/move constructor. In C++11 you have to pass the constructor parameters as their own braced-init-list. This means you aren't copying FooC
's but instead copy-list-initializing the FooC
's in the array which calls the 2 parameter constructor instead of the copy/move constructor.
FooC array[2] = {
{1, 2},
{3, 4}
};
C++17:
You no longer have temporary objects in the braced-init-list and each element of the array will be directly initialized instead of copy initialized.
Is it possible to force in this example the calling of constructor with the parameters and still delete the default, move and copy constructor?
No with your current syntax (before C++17) and yes (in C++17).
Pre-C++17:
This is not possible. The aggregate initialization copies the initializers into the aggregate. This means you have to have an accessible copy/move constructor. In C++11 you have to pass the constructor parameters as their own braced-init-list. This means you aren't copying FooC
's but instead copy-list-initializing the FooC
's in the array which calls the 2 parameter constructor instead of the copy/move constructor.
FooC array[2] = {
{1, 2},
{3, 4}
};
C++17:
You no longer have temporary objects in the braced-init-list and each element of the array will be directly initialized instead of copy initialized.
edited yesterday
answered yesterday
NathanOliver
82.5k15111172
82.5k15111172
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
add a comment |
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
I'd be careful with the phrasing here. Your pre-C++17 example is copy-list-initializing the elements.
– T.C.
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
@T.C. Wording updated.
– NathanOliver
yesterday
add a comment |
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5
use C++17 :-)...
– marcinj
yesterday
1
Since you've deleted default copy and move constructors (as well as assignment oprators) your class is no longer movable and copyable, when your program expecting move assignable class.
– Victor Gubin
yesterday
2
Have you tried removing the
=
– JVApen
yesterday
1
And
constexpr FooC(uint16_t iPort, uint16_t iPin) noexcept
– Victor Gubin
yesterday
Note that you don't need to delete the move-constructor: when you delete the copy-constructor, the move-constructor is not implicitly generated
– M.M
yesterday