In your example, _In_
means that
- VS Code Analysis will validate that callers pass a non-null pointer to an initialized buffer.
- VS Code Analysis will not validate that
t
is checked for null before dereferencing it in the function;t
is assumed to be non-null in the function itself. By changing_In_
to_In_opt_
, VS Code Analysis will validate thatt
is checked for null before dereferencing it. - VS Code Analysis will validate that the function only reads "one element" of
type
from the memory pointed at byt
, like assigning the value of the dereferenced pointer to a variable.