若参数是临时量,则 forward_as_tuple 不延续其生存期;必须在完整表达式结尾前使用它们。 示例运行此代码 #include <iostream> #include #include <tuple> #include <string> int main() { std::map<int, std::string> m; m.emplace(std::piecewise_construct, std::forward_as_tuple(10), std::forward...
最后，forward_as_tuple生成一个引用元组，但是引用的东西仍然必须存储在 * 某个地方 *。
如果你想以元组的形式储存东西，你可以。只需在lambda中捕获元组，然后使用std::get在lambda的主体中访问...
get_one返回一个prvalue。为了将其传递给forward_as_tuple，创建了一个临时对象，然后得到的元组引用该...
所以它们是lvalue，如果没有std::forward，它们总是以这样的方式传递给std::forward_as_tuple。
若实参是临时量,则 forward_as_tuple 不延续其生存期;必须在完整表达式结尾前使用它们。 示例运行此代码 #include <iostream> #include #include <string> #include <tuple> int main() { std::map<int, std::string> m; m.emplace(std::piecewise_construct, std::forward_as_tuple(6), std::forward...
We’ll start withstd::forward_as_tuple: This takes its arguments and produces a tuple of corresponding references. int x; // produces std::tuple<int&, std::string&&> std::forward_as_tuple(x, std::string(L"hello")); Note that this potentially contains a tuple of rvalue references, ...
C++ Tuple::forward_as_tuple() Function - The C++ std::tuple::forward_as_tuple() function is used to construct a tuple by fowarding its arguments, preserving their original types and forwarding them as rvalue references. unlike the std::make_tuple() funct
La Vigne says this year’s Build event represents an important moment for Microsoft, as it works to introduce rank-and-file developers to a new frontier in development. “I see the world changing. In fact, it already has—it’s just that not everyone in the mainstream has realized it yet...
as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) Elementary string conversions to_chars (C++17) from_chars (C++17) chars_format...