- auto i = std::find_if(
- std::begin(this->mapping), std::end(this->mapping),
- [layer_id](struct layer const &l) { return layer_id == l.layer_id; });
- return i == this->mapping.end() ? nullopt : optional<struct LayoutState *>(&i->state);
+ auto i = this->mapping.find(layer_id);
+ return i == this->mapping.end()
+ ? nullopt
+ : optional<struct LayoutState *>(&i->second.state);