This is probably in your code editor and the purpose is to allow you to see more "context" code. Thus if you close a block of code you see more of what follows underneath.
0
justin
On
sorry in advance - not sure if this is too simple.
perhaps this is the subscript operator.
the primary use for this is to access a specific array element:
const int array[2] = {0,1};
const int value(array[0]); // access element 0 of `array`
This is probably in your code editor and the purpose is to allow you to see more "context" code. Thus if you close a block of code you see more of what follows underneath.