Shouldn't `Default` be implemented for `Size<T>`?

Currently as of v0.12.1 the struct Size<T> does not implement Default and I believe it probably should (which is something that is not needed per se, but is idiomatic and simple). I hope there is no problem related to compile sizes or micro-optimizations, but otherwise, it would be applied as the following if I’m not wrong:

impl<T: std::default::Default> std::default::Default for Size<T> {
    fn default() -> Self {
        Self { width: T::default(), height: T::default() }

Note: there are consts for (0.0, 0.0), (1.0, 1.0) and infinity, but those are only for Size<f32> for obvious reasons, and there are no others for any other type T.

What would be the use case for a default?