Re-directing non-www subdomains with NGINX

Lets say you are hosting www.example.com with an NGINX front-end and you want to re-direct http://example.com and https://example.com to http://www.example.com. Here is the NGINX config to do that

server {
	listen 80;
	server_name example.com;
	return 302 https://www.example.com$request_uri;
}

server {
	listen 443;
	server_name example.com;
	return 302 https://www.example.com$request_uri;
}

server {
	listen	443 default_server ssl;
	client_max_body_size	4M;
	
	...

}