Scope-Bound Resource Management, see RAII 作用域限定资源管理
SCARY
Seemingly erroneous (appearing Constrained by conflicting generic parameters), but Actually work with the Right implementation (unconstrained bY the conflict due to minimized dependencies). 看起来错误(表面上由冲突的泛型参数制约),但实际上在正确的实现中有效(由于最小化依赖而无需约束)。