Chore: Make some Maps into real Sets

[arturmelanchyk]

No description provided.

[RPRX]

麻烦基于 07c35ed rebase 一下

[arturmelanchyk]

Hi @RPRX
the branch has been rebased

[RPRX]

这是在解决什么问题？Golang 的新行为？

[RPRX]

虽然 struct{} 在 Golang 中地位确实特殊

有相关解释发来看一下吗

[RPRX]

你的意思是反正存储 true 或 false 都用不到，不如用空值 struct{}？

[arturmelanchyk]

@RPRX
in this specific case map[string]bool is used as a Set, to keep unique values as keys of the map. The bool is redundant and not needed. By having struct{} instead of irrelevant bool values we avoid unneeded memory allocation as well as we avoid confusion for developers

[RPRX]

这下真把 map 用成集合了