NAME¶

std::allocator_traits::max_size - std::allocator_traits::max_size

Synopsis¶

Defined in header <memory>
static size_type max_size( const Alloc& a ) noexcept; (since C++11)
(until C++20)
static constexpr size_type max_size( const Alloc& a ) noexcept; (since C++20)

If possible, obtains the maximum theoretically possible allocation size from the
allocator a, by calling a.max_size().

If the above is not possible (e.g. Alloc does not have the member function
max_size()), then returns std::numeric_limits<size_type>::max() /
sizeof(value_type).

Parameters¶

a - allocator to detect

Return value¶

Theoretical maximum allocation size.

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2162 C++11 max_size was not requied to be noexcept required
LWG 2466 C++11 theoretical maximum allocation size in bytes size in elements is
was returned as fallback returned

See also¶

max_size returns the largest supported allocation size
(until C++20) (public member function of std::allocator<T>)