error: ‘RS2_OPTION_HDR_ENABLED’ was not declared in this scope

This error message indicates that the compiler could not find a declaration for the constant variable "RS2_OPTION_HDR_ENABLED" in the current scope.

There are a few possible reasons why this error might occur:

1. The constant variable "RS2_OPTION_HDR_ENABLED" is not defined or declared in the current source file or header file.

2. The constant variable "RS2_OPTION_HDR_ENABLED" is defined in a different namespace or header file than the one being used in the current scope.

3. There is a typo or syntax error in the code that is preventing the constant variable from being recognized by the compiler.

To resolve this error, you may need to check the header files and namespaces being used in the current scope, and ensure that the constant variable is properly declared and defined. You may also need to check for any typos or syntax errors in the code.