wp-includes/class-wp-theme.php:1182Returns the absolute path to the directory of a theme's "template" files.
string public function get_template_directory() { if ( $this->parent() ) { $theme_root = $this->parent()->theme_root; } else { $theme_root = $this->theme_root; } return $theme_root . '/' . $this->template; }Introduced in 3.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-theme.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.