# std::inplace_vector<T,N>::resize

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< cpp‎ | container‎ | inplace vector

constexpr void resize( size_type count ); | (1) | (since C++26)
constexpr void resize( size_type count, const value_type& value ); | (2) | (since C++26)

Resizes the container to contain count elements, does nothing if count == size().

If the current size is greater than count, the container is reduced to its first count elements.

If the current size is less than count, then:

1) Additional default-inserted elements are appended.
2) Additional copies of value are appended.

### Parameters

count | - | new size of the container
value | - | the value to initialize the new elements with
Type requirements
- `T` must meet the requirements of DefaultInsertable in order to use overload (1).
- `T` must meet the requirements of CopyInsertable in order to use overload (2).

### Complexity

Linear in the difference between the current size and count.

### Exceptions

1,2) Throws std::bad_alloc if count > N.

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

### Example

Run this code

    #include <inplace_vector>
    #include <print>

    int main()
    {
        std::inplace_vector<int, 6> v(6, 9);
        std::println("Initially, v = {}", v);

        v.resize(2);
        std::println("After resize(2), v = {}", v);

        v.resize(4);
        std::println("After resize(4), v = {}", v);

        v.resize(6, -1);
        std::println("After resize(6, -1), v = {}", v);

        try
        {
            std::print("Trying resize(13): ");
            v.resize(13); // throws, because count > N; v is left unchanged
        }
        catch(const std::bad_alloc& ex)
        {
            std::println("ex.what(): {}", ex.what());
        }
        std::println("After exception, v = {}", v);
    }

Possible output:

    Initially, v = [9, 9, 9, 9, 9, 9]
    After resize(2), v = [9, 9]
    After resize(4), v = [9, 9, 0, 0]
    After resize(6, -1), v = [9, 9, 0, 0, -1, -1]
    Trying resize(13): ex.what(): std::bad_alloc
    After exception, v = [9, 9, 0, 0, -1, -1]

### See also

max_size [static] | returns the maximum possible number of elements (public static member function)
size | returns the number of elements (public member function)
capacity [static] | returns the number of elements that can be held in currently allocated storage (public static member function)
empty | checks whether the container is empty (public member function)

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