wp-includes/theme.php:3231Checks a theme's support for a given feature before loading the functions which implement it.
$featurestring$filestringboolfunction require_if_theme_supports( $feature, $file ) { if ( current_theme_supports( $feature ) ) { require $file; return true; } return false;}Introduced in 2.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/theme.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.