What is ^ in object definition?

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What does the caret mean in C++/CLI?
In C++/CLR, what does a hat character ^ do?

I created my first Win form application in Visual Studio C++, and browsing through the code saw something that I cannot understand:

private: System::Windows::Forms::Button^  button1;

What is the meaning of ^ sign in this line? I understand * and & but never seen ^ in definition of an object.

It's a hat pointer. Look here: http://stackoverflow.com/q/500580 — Lumi, Dec 17 '11 at 19:41
This is due to the fact that a Windows Forms application is not a C++ program but a C++/CLI (C++ for .NET, if you like) program, which are two different languages (though quite related). If you know about this fact and indeed want to use C++/CLI, then get a good tutorial/book about C++/CLI, as the `^` thing is an essential concept. If not, then rather use some other GUI library for C++. — Christian Rau, Dec 17 '11 at 19:45

score 4 · Accepted Answer · answered Dec 17 '11 at 19:42

4

Have a look here this is not just C++ but C++/CLI

In C++/CLI the only type of pointer is the normal C++ pointer, and the .NET reference types are accessed through a "handle", with the new syntax ClassName^ instead of ClassName*. This new construct is especially helpful when managed and standard C++ code is mixed; it clarifies which objects are under .NET automatic garbage collection and which objects the programmer must remember to explicitly destroy.

answered Dec 17 '11 at 19:42

Emond

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+1 The only answer taking the probable chance into account that the OP isn't aware of the difference between C++ and C++/CLI. – Christian Rau Dec 17 '11 at 19:47

score 2 · Answer 2 · answered Dec 17 '11 at 19:40

It designates a garbage collected pointer. The normal C++ version is * for pointers, C++/CLI uses ^ to differentiate between managed and unmanaged. It also uses a different keyword to allocate the memory.

int* plain_cpp = new int;
delete plain_cpp; // unmanaged

int^ cpp_cli = gcnew int;
// managed, no delete possible

score 1 · Answer 3 · answered Dec 17 '11 at 19:41

1

It's equivalent to a pointer (*) in C++/CLI. One key difference is that it is garbage collected, since C++/CLI is managed.

answered Dec 17 '11 at 19:41

K Mehta

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score 0 · Answer 4 · answered Dec 17 '11 at 19:40

0

^ means it is a CLR type and not a C++ native type

answered Dec 17 '11 at 19:40

Arnon Rotem-Gal-Oz

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What is ^ in object definition?

4 Answers4