std::basic_string<CharT,Traits,Allocator>::max_size

< cpp‎ | string‎ | basic string
size_type max_size() const;
 (until C++11)
size_type max_size() const noexcept;
 (since C++11)
(until C++20)
constexpr size_type max_size() const noexcept;
 (since C++20)

Returns the maximum number of elements the string is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest string.

Parameters

(none)

Return value

Maximum number of characters.

Complexity

Constant.

Example

#include <iostream>
#include <string>
#include <climits>
 
int main()
{
    std::string s;
    std::cout << "Maximum size of a string is " << s.max_size()
              << " (pointer size: " << CHAR_BIT*sizeof(void*)
              << " bits)\n";
}

Possible output:

Maximum size of a string is 9223372036854775807 (pointer size: 64 bits)

See also

 returns the number of characters
(public member function)
(C++17)
 returns the maximum number of characters
(public member function of std::basic_string_view<CharT,Traits>)