Defines whether Checked Iterators are enabled. If defined as 1, unsafe iterator use causes a runtime error. If defined as 0, checked iterators are disabled. The exact behavior of the runtime error depends on the value of _SECURE_SCL_THROWS. The default value for _SECURE_SCL is 1, meaning checked iterators are enabled by default.
To enable checked iterators, set _SECURE_SCL to 1:
#define _SECURE_SCL 1
To disable checked iterators, set _SECURE_SCL to 0:
#define _SECURE_SCL 0
For information on how to disable warnings about checked iterators, see _SCL_SECURE_NO_WARNINGS.