wp-includes/class-wp-styles.php:307Adds extra CSS styles to a registered stylesheet.
$handlestring$codestringbool public function add_inline_style( $handle, $code ) { if ( ! $code ) { return false; } $after = $this->get_data( $handle, 'after' ); if ( ! $after ) { $after = array(); } $after[] = $code; return $this->add_data( $handle, 'after', $after ); }Introduced in 3.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-styles.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.