std::deque<T,Allocator>::push_front
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std::deque
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deque::push_front
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void push_front( const T& value );
(1)
(constexpr since C++26)
void push_front( T&& value );
(2)
(since C++11) (constexpr since C++26)
Prepends a copy of value to the beginning of the container.
All iterators (including the end() iterator) are invalidated. No references are invalidated.
[edit] Parameters
value
-
the value of the element to prepend
Type requirements
-
If the following condition is satisfied, the behavior is undefined:
(since C++11)[edit] Complexity
Constant.
[edit] Exceptions
If an exception is thrown for any reason, these functions have no effect (strong exception safety guarantee).
[edit] Example
Run this code
#include <deque> #include <iomanip> #include <iostream> #include <string> int main() { std::deque <std::string > letters; letters.push_front("me"); // overload (1) std::string s{"send"}; letters.push_front(std::move(s)); // overload (2) std::cout << "std::deque letters holds: "; for (auto&& e : letters) std::cout << std::quoted (e) << ' '; std::cout << "\nMoved-from string s holds: " << std::quoted (s) << '\n'; }
Possible output:
std::deque letters holds: "send" "me" Moved-from string s holds: ""