<:< and <%< work similarly, but with slight variations:
A =:= B means A must be exactly B A <:< B means A must be a subtype of B (analogous to the simple type constraint <:) A <%< B means A must be viewable as B, possibly via implicit conversion (analogous to the simple type constraint <%) 此内容由惯性聚合(RSS阅读器)自动聚合整理，仅供阅读参考。 原文来自 — 版权归原作者所有。