c++ - 是否有关于 std::move 的这种使用的编译警告？

Question

以下程序显示了 std::move() 的两个有问题(但技术上有效)的用法。 .是否可以使用 LLVM 获得有关这些的编译警告？我注意到还有其他一些上下文的诊断信息，其中 std::move是多余的。

我用 bcc32c 5.0.2 版(基于 LLVM 5.0.2)编译了这个，没有收到任何警告。

#include <vector>

int main() {
    const std::vector<int> a = {1, 2, 3};
    std::vector<int> b = {3, 4, 5};

    std::vector<int> c = std::move(a); // std::move from const

    std::vector<int> d = std::move(b);

    std::vector<int> e = b; // used after std::move
}

Answer 1

叮叮当当的 bugprone-use-after-move checker 支持这种诊断:

bugprone-use-after-move

Warns if an object is used after it has been moved, for example:

std::string str = "Hello, world!\n";
std::vector<std::string> messages;
messages.emplace_back(std::move(str));
std::cout << str;

The last line will trigger a warning that str is used after it has been moved.

[...]

Use

Any occurrence of the moved variable that is not a reinitialization (see below) is considered to be a use.

[...]

If multiple uses occur after a move, only the first of these is flagged.