cannot perform pointer arithmetic

this->user_informati on->Text =
this->query->SList[this->listBox1->SelectedInde x];

sList is a SortedList i want to reach its valur by its index ??? i got this
error
error C2845: '[' : cannot perform pointer arithmetic on __gc pointer
'System::Collec tions::SortedLi st __gc *'

[Doug Harrison [MVP]]

<sadun> wrote:

this->user_informati on->Text =
this->query->SList[this->listBox1->SelectedInde x];

sList is a SortedList i want to reach its valur by its index ??? i got this
error
error C2845: '[' : cannot perform pointer arithmetic on __gc pointer
'System::Colle ctions::SortedL ist __gc *'

Try using the Item method, e.g.

a->Item[n];

The problem is that the current incarnation of Managed C++ represents
objects of reference types as pointers, for which operator[] already has a
meaning in C++. Though it's disallowed for managed pointers, it's still part
of the language, hence the error message. Unfortunately, this messiness
means Managed C++ currently doesn't support the nice indexer syntax you have
in other languages. This problem is addressed in the upcoming Whidbey
compiler, which provides many improvements in the Managed C++ syntax.

--
Doug Harrison
Microsoft MVP - Visual C++

thanks for information...

there is a method exists for SortedList

this->query->SList->GetByIndex(thi s->listBox1->SelectedIndex) ;

[Doug Harrison [MVP]]

<sadun> wrote:

thanks for information...

there is a method exists for SortedList

this->query->SList->GetByIndex(thi s->listBox1->SelectedIndex) ;

Yep, that seems to be what you needed. The indexer and Item property take a
key to look up as their argument and return the associated value for
SortedList.

--
Doug Harrison
Microsoft MVP - Visual C++