相关疑难解决方法(0)

标准是否定义了此代码会发生什么？

#include <iostream>

template <typename Func>
void callfunc(Func f)
{
   ::std::cout << "In callfunc.\n";
    f();
}

template <typename Func>
void callfuncref(Func &f)
{
   ::std::cout << "In callfuncref.\n";
    f();
}

int main()
{
    int n = 10;
    // n is captured by value, and the lambda expression is mutable so
    // modifications to n are allowed inside the lambda block.
    auto foo = [n]() mutable -> void {
       ::std::cout << "Before increment n == " << n << '\n';
       ++n;
       ::std::cout …