Why do I get an exception for this usage of enable_shared_from_this()?
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2
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On the following example below, something is escaping me. Why does this generate the usual weak_ptr exception when using the shared_from_this, if there is an outstanding shared_ptr reference to the object which calls it ?
class A : std::enable_shared_from_this<A>
public:
static std::shared_ptr<A> create()
return std::shared_ptr<A>(new A());
A()
void setParent(const std::shared_ptr<A>& other)
std::shared_ptr<A> keep()
auto o = A::create();
o->setParent(shared_from_this());
return o;
;
int main()
std::shared_ptr<A> a = A::create();
auto s = a->keep();
c++ c++11 std
asked Nov 9 at 21:09
user2123288
432716
add a comment |
up vote
2
down vote
favorite
On the following example below, something is escaping me. Why does this generate the usual weak_ptr exception when using the shared_from_this, if there is an outstanding shared_ptr reference to the object which calls it ?
class A : std::enable_shared_from_this<A>
public:
static std::shared_ptr<A> create()
return std::shared_ptr<A>(new A());
A()
void setParent(const std::shared_ptr<A>& other)
std::shared_ptr<A> keep()
auto o = A::create();
o->setParent(shared_from_this());
return o;
;
int main()
std::shared_ptr<A> a = A::create();
auto s = a->keep();
c++ c++11 std
asked Nov 9 at 21:09
user2123288
432716
1
->public std::enable_shared_from_this<A>.
– Jarod42
Nov 9 at 21:14
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
On the following example below, something is escaping me. Why does this generate the usual weak_ptr exception when using the shared_from_this, if there is an outstanding shared_ptr reference to the object which calls it ?
class A : std::enable_shared_from_this<A>
public:
static std::shared_ptr<A> create()
return std::shared_ptr<A>(new A());
A()
void setParent(const std::shared_ptr<A>& other)
std::shared_ptr<A> keep()
auto o = A::create();
o->setParent(shared_from_this());
return o;
;
int main()
std::shared_ptr<A> a = A::create();
auto s = a->keep();
c++ c++11 std
asked Nov 9 at 21:09
user2123288
432716
On the following example below, something is escaping me. Why does this generate the usual weak_ptr exception when using the shared_from_this, if there is an outstanding shared_ptr reference to the object which calls it ?
class A : std::enable_shared_from_this<A>
public:
static std::shared_ptr<A> create()
return std::shared_ptr<A>(new A());
A()
void setParent(const std::shared_ptr<A>& other)
std::shared_ptr<A> keep()
auto o = A::create();
o->setParent(shared_from_this());
return o;
;
int main()
std::shared_ptr<A> a = A::create();
auto s = a->keep();
c++ c++11 std
c++ c++11 std
asked Nov 9 at 21:09
user2123288
432716
asked Nov 9 at 21:09
user2123288
432716
asked Nov 9 at 21:09
user2123288
432716
asked Nov 9 at 21:09
user2123288
432716
asked Nov 9 at 21:09
user2123288
432716
432716
1
->public std::enable_shared_from_this<A>.
– Jarod42
Nov 9 at 21:14
add a comment |
1
->public std::enable_shared_from_this<A>.
– Jarod42
Nov 9 at 21:14
1
1
->
public std::enable_shared_from_this<A>.– Jarod42
Nov 9 at 21:14
->
public std::enable_shared_from_this<A>.– Jarod42
Nov 9 at 21:14
add a comment |
2 Answers
2
active
oldest
votes
up vote
3
down vote
You need to inherit publicly from enable_shared_from_this so the shared ptr ctor can see it.
As an aside, clang fails to compile your example due to this.
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin Thatshared_from_thisis inaccessible.
– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add#include <memory>and it compiles fine.
– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
add a comment |
up vote
2
down vote
enable_shared_from_this must be an unambiguous and accessible base of A for the library to handle the internal weak pointer correctly.
Your inheritance is private (the default when using the class keyword).
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
You need to inherit publicly from enable_shared_from_this so the shared ptr ctor can see it.
As an aside, clang fails to compile your example due to this.
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin Thatshared_from_thisis inaccessible.
– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add#include <memory>and it compiles fine.
– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
add a comment |
up vote
3
down vote
You need to inherit publicly from enable_shared_from_this so the shared ptr ctor can see it.
As an aside, clang fails to compile your example due to this.
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin Thatshared_from_thisis inaccessible.
– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add#include <memory>and it compiles fine.
– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
add a comment |
up vote
3
down vote
up vote
3
down vote
You need to inherit publicly from enable_shared_from_this so the shared ptr ctor can see it.
As an aside, clang fails to compile your example due to this.
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
You need to inherit publicly from enable_shared_from_this so the shared ptr ctor can see it.
As an aside, clang fails to compile your example due to this.
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
answered Nov 9 at 21:16
Yakk - Adam Nevraumont
178k19185363
178k19185363
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin Thatshared_from_thisis inaccessible.
– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add#include <memory>and it compiles fine.
– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
add a comment |
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin Thatshared_from_thisis inaccessible.
– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add#include <memory>and it compiles fine.
– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
Thanks. Yes that was it, although the example compiled ok, and I even stepped debug it to confirm it was being raised by the shared_from_this(). Thanks!
– user2123288
Nov 9 at 21:20
What error does clang give?
– Kevin
Nov 9 at 21:45
What error does clang give?
– Kevin
Nov 9 at 21:45
@Kevin That
shared_from_this is inaccessible.– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Kevin That
shared_from_this is inaccessible.– Yakk - Adam Nevraumont
Nov 9 at 22:13
@Yakk-AdamNevraumont I don't see this. All I did was add
#include <memory> and it compiles fine.– Kevin
Nov 10 at 0:40
@Yakk-AdamNevraumont I don't see this. All I did was add
#include <memory> and it compiles fine.– Kevin
Nov 10 at 0:40
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
@kevin Probably different version of clang; I used stacked crooked.
– Yakk - Adam Nevraumont
Nov 10 at 1:31
add a comment |
up vote
2
down vote
enable_shared_from_this must be an unambiguous and accessible base of A for the library to handle the internal weak pointer correctly.
Your inheritance is private (the default when using the class keyword).
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
add a comment |
up vote
2
down vote
enable_shared_from_this must be an unambiguous and accessible base of A for the library to handle the internal weak pointer correctly.
Your inheritance is private (the default when using the class keyword).
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
add a comment |
up vote
2
down vote
up vote
2
down vote
enable_shared_from_this must be an unambiguous and accessible base of A for the library to handle the internal weak pointer correctly.
Your inheritance is private (the default when using the class keyword).
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
enable_shared_from_this must be an unambiguous and accessible base of A for the library to handle the internal weak pointer correctly.
Your inheritance is private (the default when using the class keyword).
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
answered Nov 9 at 21:17
StoryTeller
89.7k12180246
89.7k12180246
add a comment |
add a comment |
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1
->
public std::enable_shared_from_this<A>.– Jarod42
Nov 9 at 21:14