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

 

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std::inplace_vector

Member types
Member functions
inplace_vector::inplace_vector inplace_vector::~inplace_vector    inplace_vector::operator= inplace_vector::assign inplace_vector::assign_range Size and capacity inplace_vector::empty inplace_vector::size inplace_vector::max_size inplace_vector::capacity inplace_vector::resize inplace_vector::reserve inplace_vector::shrink_to_fit Iterators inplace_vector::begininplace_vector::cbegin inplace_vector::endinplace_vector::cend inplace_vector::rbegininplace_vector::crbegin inplace_vector::rendinplace_vector::crend	Element access inplace_vector::at inplace_vector::operator[] inplace_vector::front inplace_vector::back inplace_vector::data Modifiers inplace_vector::clear inplace_vector::erase inplace_vector::swap inplace_vector::insert inplace_vector::insert_range inplace_vector::emplace inplace_vector::emplace_back inplace_vector::try_emplace_back inplace_vector::unchecked_emplace_back inplace_vector::push_back inplace_vector::try_push_back inplace_vector::unchecked_push_back inplace_vector::pop_back inplace_vector::append_range inplace_vector::try_append_range
Non-member functions
erase(std::inplace_vector)erase_if(std::inplace_vector) swap(std::inplace_vector)	operator==operator<=>

 

static constexpr void reserve( size_type new_cap );		(since C++26)

Does nothing, except that may throw std::bad_alloc. The request to increase the capacity (i.e., the internal storage size) is ignored because std::inplace_vector<T, N> is a fixed-capacity container.

Parameters

new_cap

-

new capacity of the inplace_vector, in number of elements

Return value

(none)

Complexity

Constant.

Exceptions

std::bad_alloc if new_cap > capacity() is true.

Notes

This function exists for compatibility with vector-like interfaces.

Example

Run this code

#include <cassert>
#include <inplace_vector>
#include <iostream>
 
int main()
{
    std::inplace_vector<int, 4> v{1, 2, 3};
    assert(v.capacity() == 4 && v.size() == 3);
 
    v.reserve(2); / does nothing
    assert(v.capacity() == 4 && v.size() == 3);
 
    try
    {
        v.reserve(13); / throws, because requested capacity > N; v is left unchanged
    }
    catch(const std::bad_alloc& ex)
    {
        std::cout << ex.what() << '\n';
    }
    assert(v.capacity() == 4 && v.size() == 3);
}

Possible output:

std::bad_alloc

See also

size	returns the number of elements (public member function)
max_size [static]	returns the maximum possible number of elements (public static member function)
resize	changes the number of elements stored (public member function)
capacity [static]	returns the number of elements that can be held in currently allocated storage (public static member function)
shrink_to_fit [static]	reduces memory usage by freeing unused memory (public static member function)

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