Currently configuring the _scheme and _method requirement in routes is pretty strange and also wrong in some cases. Current example:

route_name:
    pattern: /hello/{slug}
    hostname_pattern: {locale}.example.com
    requirements:
        locale: en|fr
        slug: \w+
        _scheme: HTTPS
        _method: GET|POST
    defaults:
        _controller: Foo:bar:baz

The problems are:

1. variables in the requirement section reference placeholders. Except for _scheme and _method!
2. these requirements allow regular expressions. But this is not true for _scheme and _method because many places of the routing component expect a delimited list like GET|POST. So normal regex like .+ does not work for them and breaks code.

My proposal:

route_name:
    pattern: /hello/{slug}
    hostname_pattern: {locale}.example.com
    schemes: HTTPS
    methods: [GET, POST]
    requirements:
        locale: en|fr
        slug: \w+
    defaults:
        _controller: Foo:bar:baz

This makes these scheme and method an option like pattern which is much more consistent as they are on the "same level" as the path pattern because all of them belong to the HTTP request (method + URL). One can also clearly define that not any regex is valid but only a single string or an array of allowed methods.