std::inplace_vector<T,N>::emplace

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)….

# Declarations

template< class... Args >
constexpr iterator emplace( const_iterator position, Args&&... args );

(since C++26)

# Parameters

pos: iterator before which the new element will be constructed
args: arguments to forward to the constructor of the element

# Return value

An iterator to the inserted element.

# Example

#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';
    }
}