# `set_logtalk_flag/2`

## Description

    set_logtalk_flag(Flag, Value)

Sets global, default, flag values. For local flag scope, use the corresponding set_logtalk_flag/2 directive. To set a global flag value when compiling and loading a source file, wrap the calls to this built-in predicate with an initialization/1 directive. For a description of the predefined compiler flags, please see the Compiler flags section in the User Manual.

## Modes and number of proofs

    set_logtalk_flag(+atom, +nonvar) - one

## Errors

`Flag` is a variable:
`instantiation_error`
`Value` is a variable:
`instantiation_error`
`Flag` is neither a variable nor an atom:
`type_error(atom, Flag)`
`Flag` is an atom but an invalid flag:
`domain_error(flag, Flag)`
`Value` is not a valid value for flag `Flag`:
`domain_error(flag_value, Flag + Value)`
`Flag` is a read-only flag:
`permission_error(modify, flag, Flag)`

## Examples

    % turn off globally and by default the compiler
    % unknown entities warnings:
    | ?- set_logtalk_flag(unknown_entities, silent).

See also

create_logtalk_flag/3, current_logtalk_flag/2