使用绑定的noexcept保存
我在 < 中保存 noexcept 说明符时遇到问题代码>std::bind，使用C++17。 在 GCC 和 Clang 中没有保留，但在 MSVC 中是。似乎将 bind 与带有 noexcept 说明符的函数一起使用，生成的对象不会保留它，始终考虑到它不是 noexcept 。
具有如下功能：
void f(int) noexcept;
现在创建一个带有 std::bind 的可调用对象：
auto g = std::bind(f,5);
可以看出 noexcept 行为在 f 之间是不同的在 GCC 和 Clang 中执行时（使用 C++17 模式）和 g
std::cout << noexcept(f(5)); //prints 1, ok, as expected
std::cout << noexcept(g()); //prints 0, WRONG!!
正如开头提到的，MSVC 是唯一具有（在我看来）一致行为的。阅读标准规范没有提到任何相关内容，所以也许没有指定这种行为 那么，这是由于标准中缺乏规范而导致的正常行为还是一个错误？
使用 bind 时有什么方法可以强制使用“noexcept”说明符？
I have a problem with preservation of noexcept specifier in std::bind, using C++17.
In GCC and Clang is not preserved, but in MSVC it is. It seems that using bind with a function with noexcept specifier, the resulting object doesn't preserve it, considering always that it isn't noexcept.
Having a function like:
void f(int) noexcept;
And now creating a callable with std::bind on it:
auto g = std::bind(f,5);
It can be seen that noexcept behaviour is different between f and g when executing in GCC and Clang (using C++17 mode)
std::cout << noexcept(f(5)); //prints 1, ok, as expected
std::cout << noexcept(g()); //prints 0, WRONG!!
As mentioned at the beginning, MSVC is the only with (in my opinion) consistent behaviour. Reading the standard specification doesn't mention anything about that, so maybe this behaviour is not specified
So, is this a normal behaviour because the lack of specification in the standard or is a bug?
Is any way to force the "noexcept" specifier when using bind?
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如果您可以使用 C++20，那么您可以使用
std ::bind_front，不仅性能比std::bind更好，而且完美转发的operator()称呼如果它调用的std::invoke表达式是noexcept，它返回的包装器是noexcept（换句话说，它保留异常底层调用运算符的规范），因此以下static_assert可以传递给所有三个编译器演示
If you can use C++20, then you can just use
std::bind_front, which not only has better performance thanstd::bind, but theoperator()of the perfect forwarding call wrapper it returns isnoexceptif thestd::invokeexpression it calls isnoexcept(in other words, it preserves the exception specification of the underlying call operator), so the followingstatic_assertcan pass for all three compilersDemo