是否允许指针作为有序 STL 容器中的键?
this other question询问如何比较指针应该如何解释 wrt C++ Std.
There's this other question asking about how comparing pointers is supposed to be interpreted wrt the C++ Std.
所以我想知道 C++ 标准对在有序标准库 (STL) 容器中使用指针作为键有什么看法――即是否允许拥有
So I was wondering what the C++ Std has to say about using pointers as keys in ordered standard library (STL) containers -- i.e. is one allowed to have
std::map
这是由于 std::less 或 内置运算符 < 的规范造成的吗?
and is this due to the specification of std::less or builtin operator <?
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是的，因为它使用了 std::less，即使 也需要产生全序. 没有.(< 将被允许将来自不同序列的不同指针视为相同，如果您插入来自不同序列的指针，这将导致 map 等的奇怪行为.
Yes, because it uses std::less, which is required to result in a total order even if < doesn't. (< would be allowed to treat different pointers from distinct sequences as equal, which would result in an odd behaviour of map etc if you insert pointers from different sequences).
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