hmmm initialise in the loop start, loop_end shouldn't ever be called without loop_start

gistfile1.php

<?php

add_action( 'loop_start', 'qd_loop_start' );
add_action( 'loop_end',   'qd_loop_end' );
 
function qd_loop_start( $query ) {
	global $query_depth;
	if(!isset($query_depth)){
		$query_depth = 0;
	}
	$query_depth++;
}
 
function qd_loop_end( $query ) {
	global $query_depth;
	$query_depth--;
}


function get_query_depth(){
	global $query_depth;
	if(!isset($query_depth)){
		$query_depth = 0;
	}

	return $query_depth;
}

function my_in_main_loop() {
	$result = ( get_query_depth() == 1) && ( is_main_query() ) );
	return $result;
}

note to self, needs another bit of code to initialize $query_depth other than get_query_depth itself