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

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 ) ... .

Parameters

Return value

An iterator to the inserted element.

Complexity

Linear: the distance between pos and end of the container + 1 .

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

#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';
    }
}

std::bad_alloc

See also