Method not found depending on the order of impl traits.

[esdrubal]

script;

struct SomeStruct<T> {
    cap: u64,
}

trait AbiEncode2 {
    fn abi_encode2(self, ref mut buffer: Buffer);
}

impl<T> AbiEncode2 for SomeStruct<T> where T: AbiEncode2
{
    fn abi_encode2(self, ref mut buffer: Buffer) {
        self.cap.abi_encode2(buffer);
    }
}

impl AbiEncode2 for u64
{
    fn abi_encode2(self, ref mut buffer: Buffer) { 
    }
}

fn main() {
}

Error:

14 |     fn abi_encode2(self, ref mut buffer: Buffer) {
15 |         self.cap.abi_encode2(buffer);
   |                  ^^^^^^^^^^^ No method named "abi_encode2" found for type "u64".
16 |     }

If I change the order to:

script;

struct SomeStruct<T> {
    cap: u64,
}

trait AbiEncode2 {
    fn abi_encode2(self, ref mut buffer: Buffer);
}

impl AbiEncode2 for u64
{
    fn abi_encode2(self, ref mut buffer: Buffer) { 
    }
}

impl<T> AbiEncode2 for SomeStruct<T> where T: AbiEncode2
{
    fn abi_encode2(self, ref mut buffer: Buffer) {
        self.cap.abi_encode2(buffer);
    }
}

fn main() {
}

It works