std::inplace_vector<T,N>::emplace
From cppreference.com
template< class... Args > constexpr iterator emplace( const_iterator position, Args&&... args ); |
(since C++26) | |
Inserts a new element into the container directly before pos. Typically, the element is constructed uses placement new to construct the element in-place at the location provided by the container. The arguments args... are forwarded to the constructor as std::forward<Args>(args)....
| This section is incomplete |
Parameters
| pos | - | iterator before which the new element will be constructed |
| args | - | arguments to forward to the constructor of the element |
| Type requirements | ||
-T must meet the requirements of MoveAssignable, MoveInsertable and EmplaceConstructible.
| ||
Return value
An iterator to the inserted element.
Complexity
Linear in the distance between pos and end().
Exceptions
Throws std::bad_alloc if before the invocation size() == capacity(). The function has no effects (strong exception safety guarantee).
Any exception thrown by initialization of inserted element or by any LegacyInputIterator operation. Elements in [0, pos) are not modified.
Example
Run this code
#include <cassert>
#include <inplace_vector>
#include <new>
#include <utility>
int main()
{
using P = std::pair<int, int>;
using I = std::inplace_vector<P, 3>;
auto nums = I{{0, 1}, {2, 3}};
auto it = nums.emplace(nums.begin() + 1, -1, -2);
assert((*it == P{-1, -2}));
assert((nums == I{P{0, 1}, {-1, -2}, {2, 3}}));
try
{
nums.emplace(nums.begin(), 1, 3); // throws: no space
}
catch(const std::bad_alloc& ex)
{
std::cout << ex.what() << '\n';
}
}
Possible output:
std::bad_alloc
See also
| inserts elements (public member function) | |
| constructs an element in-place at the end (public member function) |