std::allocator_traits<Alloc>::max_size
Since C++20
static constexpr size_type max_size( const Alloc& a ) noexcept;
Since C++11, Until C++20
static size_type max_size( const Alloc& a ) noexcept;
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 was returned as fallback | size in elements is returned |