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

Conditionally appends the given element value to the end of the container.

If size ( ) == capacity ( ) is true , there are no effects. Otherwise, appends an object of type T :

No iterators or references are invalidated, except end() , which is invalidated if the insertion occurs.

Parameters

Return value

std:: addressof ( back ( ) ) if size ( ) < capacity ( ) , nullptr otherwise.

Complexity

Constant.

Exceptions

Any exception thrown by initialization of inserted element.

If an exception is thrown for any reason, these functions have no effect ( strong exception safety guarantee ).

Notes

Example

#include <cassert>
#include <inplace_vector>
#include <string>
 
int main()
{
    std::inplace_vector<std::string, 2> pets;
    std::string dog{"dog"};
 
    std::string* p1 = pets.try_push_back("cat"); // overload (1)
    assert(*p1 == "cat" and pets.size() == 1);
 
    std::string* p2 = pets.try_push_back(std::move(dog)); // overload (2)
    assert(*p2 == "dog" and pets.size() == 2);
 
    assert(pets[0] == "cat" and pets[1] == "dog");
    assert(pets.size() == pets.capacity());
 
    std::string* p3 = pets.try_push_back("bug");
    assert(p3 == nullptr and pets.size() == 2);
}

See also