funcdef assignment causes errors (+ invoking funcdef as member)

[Paril]

funcdef's are one of the weirder AS types, since they are handles but they can't be directly "assigned" to (that is to say, F @d; d = a; is an error, apparently because they are const but I wish it would allow it to just act as a regular handle assignment).

Anyways, assignment in any context is busted for them, and secondarily the langserv reports an error if attempting to invoke a funcdef value from a class.

class Bar
{
    foo_f @f;
}

funcdef void foo_f(Bar &);

void foo_impl(Bar &)
{
}

void f(foo_f @)
{
}

void test()
{
    Bar b;
    foo_f @func;

    // error: Invalid operation 'opAssign' between 'void(Bar)@' and 'void(Bar)'
    // but is valid AS.
    @func = foo_impl;

    // no error; correct
    func(b);

    // error: Cannot convert 'void(Bar)@' to parameter type 'void(Bar)@'
    // but is valid AS.
    f(func);

    // error: Invalid operation 'opAssign' between 'void(Bar)@' and 'void(Bar)'
    // but is valid AS.
    @b.f = foo_impl;

    // error: 'f' is not a method.
    // but is valid AS
    b.f(b);

    // error: Invalid operation 'opAssign' between 'void(Bar)@' and 'void(Bar)'.
    // this is correct error and AS will error on this line.
    // AS Error: ERR  : Can't implicitly convert from 'foo_f@const' to 'const foo_f&'.
    func = foo_impl;
}

[Paril]

As an addendum: this also affects is and !is operations