(C++17) | ||||
| Sequence | ||||
(C++11) | ||||
(C++26) | ||||
(C++26) | ||||
(C++11) | ||||
| Associative | ||||
| Unordered associative | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
| Adaptors | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
| Views | ||||
(C++20) | ||||
(C++23) | ||||
| Tables | ||||
| Iterator invalidation | ||||
| Member function table | ||||
| Non-member function table |
std::stack| Member functions | ||||
| Element access | ||||
| Capacity | ||||
| Modifiers | ||||
(C++23) | ||||
stack::emplace (C++11) | ||||
(C++11) | ||||
| Non-member functions | ||||
(C++11) | ||||
| Helper classes | ||||
(C++11) | ||||
(C++23) | ||||
| Deduction guides(C++17) |
template<class...Args> void emplace( Args&&...args); | (since C++11) (until C++17) | |
template<class...Args> decltype(auto) emplace( Args&&...args); | (since C++17) | |
Pushes a new element on top of the stack. The element is constructed in-place, i.e. no copy or move operations are performed. The constructor of the element is called with exactly the same arguments as supplied to the function.
Effectively callsc.emplace_back(std::forward<Args>(args)...);.
Contents |
| args | - | arguments to forward to the constructor of the element |
(none) | (until C++17) |
The value or reference, if any, returned by the above call toContainer::emplace_back. | (since C++17) |
Identical to the complexity ofContainer::emplace_back.
#include <iostream>#include <stack> struct S{int id; S(int i,double d,std::string s): id{i}{std::cout<<"S::S("<< i<<", "<< d<<",\""<< s<<"\");\n";}}; int main(){std::stack<S> stack;const S& s= stack.emplace(42,3.14,"C++");// for return value C++17 requiredstd::cout<<"id = "<< s.id<<'\n';}
Output:
S::S(42, 3.14, "C++")id = 42
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2783 | C++17 | emplace returnedreference, breaking compatibility with pre-C++17 containers | returnsdecltype(auto) |
| inserts element at the top (public member function)[edit] | |
| removes the top element (public member function)[edit] |
