【c++20】‘std::allocator＜char＞::allocate‘: function does not take 2 arguments

• C++ Dynamic memory management std::allocator

std::allocator::allocate

• 两种，c++20 后第一种不支持：
  (1)

pointer allocate( size_type n, const void* hint = 0 );
1

(until C++17)
T* allocate( std::size_t n, const void* hint );
(since C++17)
(deprecated)
(removed in C++20)

(2)