每次我需要使用std::bind时，我最终都会使用 lambda。那么我应该什么时候使用std::bind呢？我刚刚从一个代码库中删除了它，我发现 lambdas 总是比std::bind. 不是std::bind完全没有必要吗？将来不应该弃用吗？我什么时候应该更喜欢std::bindlambda 函数？（它与 lambdas 同时进入标准肯定是有原因的。）
我还注意到越来越多的人熟悉 lambda（所以他们知道 lambda 的作用）。但是，熟悉std::bind和的人要少得多std::placeholders。
Here's something you can't do with a lambda:
std::unique_ptr<SomeType> ptr = ...;
return std::bind(&SomeType::Function, std::move(ptr), _1, _2);
Lambdas can't capture move-only types; they can only capture values by copy or by lvalue reference. Though admittedly this is a temporary issue that's being actively resolved for C++14 ;)
"Simpler and clearer" is a matter of opinion. For simple binding cases, bind can take a lot less typing. bind also is focused solely on function binding, so if you see std::bind, you know what you're looking at. Whereas if you use a lambda, you have to look at the lambda implementation to be certain of what it does.
Lastly, C++ does not deprecate things just because some other feature can do what it does. auto_ptr was deprecated because it is inherently dangerous to use, and there is a non-dangerous alternative.
您可以创建使用 lambda 无法创建的多态对象std::bind，即std::bind可以使用不同的参数类型调用返回的调用包装器：
#include <functional>
#include <string>
#include <iostream>
struct Polly
{
template<typename T, typename U>
auto operator()(T t, U u) const -> decltype(t + u)
{ return t + u; }
};
int main()
{
auto polly = std::bind(Polly(), std::placeholders::_1, "confusing");
std::cout << polly(4) << polly(std::string(" this is ")) << std::endl;
}
我将其创建为一个难题，而不是一个好的代码示例，但它确实演示了多态调用包装器。