编码

这是这个看似无辜的几行代码。

#include <iostream>
#include <string>
#include <unordered_map>

struct Tag
{
    using name_t        = std::string;
    using tag_map_t     = std::unordered_map<name_t, Tag>;

    name_t              name;
    tag_map_t           children = {};
};

int main(void)
{
    auto foo = Tag{"foo"};
    auto bar = Tag{"bar"};
    foo.children["bar"] = bar;
    std::cout << foo.name << " -> " << foo.children["bar"].name << std::endl;

    return 0;
}

让我们尝试编译它

铛

? clang++ --version
clang version 11.0.1
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\LLVM\bin

? clang++ -std=c++14 -Weverything -Werror -Wno-c++98-compat tag.cpp -o tag.exe && …